# List of Seminars

 Speaker: Ujjal K. Dey Affiliation: APCTP Pohang, South Korea Title: Light dark matter through assisted annihilation Date: 23rd October(Tuesday) Time: 4:00pm (tea @ 3:45pm) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: Recent observations from direct detection experiments put stringent constraints on the popular WIMP cold dark matter (DM) models. Moreover, there are cosmological observations from the galactic scale structure formation which suggests the DM should be self-interacting and light -- the fact which is not in consonance with the WIMP paradigm. In this talk we will focus on the light dark matter scenarios where annihilation to Standard Model particles at tree-level may be kinematically forbidden. In such cases annihilation can be aided by massive Standard Model-like species, called assisters, in the initial state that enhances the available phase space opening up novel tree-level processes. We will then discuss the feasibility of such non-standard assisted annihilation processes to reproduce the observed relic density of dark matter and implications from direct detection. Finally, we shall talk about the future prospects of such DM scenarios. Speaker: Venkata S. Bhadram Affiliation: Carnegie Institute of Science, Washington D.C. Title: Matter under Extreme Pressures: A Route to Discover Metastable Materials Date: 24th September, 2018 Time: 11:00 AM(Tea at 10:50 AM) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: The ongoing technological advances demand the need for discovering new materials with intriguing properties. The oft-overlooked arena of metastable phases may yield promising new technological materials. [1-3] The metastable phases of materials are not the ground states at room conditions but can be accessed and stabilized using extreme environments, notably high-pressures and temperatures.[4,5] In my talk, I would present the discovery of two such metastable phases in Ti-N system, 1) TiN2, which is a promising superhard material that contains unique nitrogen subunits with highly energetic N―N single bonds [6] 2) Ti3N4, which is the first semiconducting titanium nitride known to date.[7] Although, these compounds possess positive enthalpies (thermodynamically unstable) at room conditions, high-pressure/temperature conditions made it possible to access and stabilize these phases. The strategy that we employed by marrying first principles theoretical calculations to high-pressure synthetic techniques to synthesize and characterize these materials is an unique approach towards discovering novel high-density and high-energy structures (metastable phases) of materials which are otherwise very difficult to be accessed. I would also talk about our efforts to stabilize photoresponsive solid solutions of zinc and manganese oxides in metastable rocksalt phase.[8] These phase-pure, chemically homogeneous and thermally stable (up to 500°C) novel solid-solutions exhibit moderate photocurrents when tested for solar light harvesting applications. Apart from photoresponse, these solid solutions exhibit interesting magnetic phase transition and field dependent magnetic behavior at low-temperatures. References: 1)W. Sun et al, Science Advances, 2, 1 (2016). 2)D. Y. Kim et al, Nature Materials, 14, 169 (2015). 3)B. Keimer, J. E. Moore, Nature Physics, 13, 1045 (2017). 4)V. V. Brazhkin, “High-Pressure Synthesized Materials: Treasures and Hints” High Pressure Research, 27, 333 (2007). 5)W. Sun et al, Thermodynamic Routes to Novel Metastable Nitrogen-Rich Nitrides, Chemistry of Materials, 29, 6936 (2017). 6)V. S. Bhadram, D. Y. Kim and T. A. Strobel. “High-Pressure Synthesis and Characterization of Titanium Pernitride.” Chemistry of Materials, 28, 1616 (2016). 7)V. S. Bhadram, H. Liu, E. Xu, T. Li, T. A. Strobel, “Semiconducting Cubic Titanium Nitride in the Th3P4 structure.” Physical Review Materials, 2, 011602 (R) (2018). 8)V. S. Bhadram, Q. Cheng, C. K. Chan, Y. Liu, K. Landskron, and T. A. Strobel, “ZnxMn1-xO Solid Solutions in the Rocksalt Structure: Optical, Charge-Transport and Photoelectrochemical Properties. ACS Applied Energy Materials, 1, 260 (2018). Speaker: Dr. K.R. Koteswara Affiliation: Technische Universitaet Dortmund, Germany Title: Quantum Information Processing and Hyperpolarization of nuclear spins using Nitrogen-Vacancy centers in diamond Date: 13th September, 2018 Time: 11:00 AM(Tea at 10:50 AM) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: Nitrogen-Vacancy (NV) centers in diamond have interesting properties for a number of quantum technologiesincluding quantum information processing and nano-scale Nuclear Magnetic Resonance (NMR). In this presentation, I will talk about our recent experimental research on NV centers for the applications of quantum information processing and hyperpolarization of nuclear spins.I will first introduce NV centers, their properties and some of their applications. Then, I will talk about interactions between single electron spins of NV centers and proximal nuclear spins and interesting level anti-crossings that occur because of these interactions. Some of the interesting results of this analysis are (i) dynamics of a single-spin driven beyond the rotating-wave approximation and (ii) decoherence-free subspaces. Next, I will talk about transferring polarization of optically pumped NV centers to bulk 13C nuclear spins of the diamond lattice. Finally, I will discuss strategies to realize scalable quantum information processing using NV centers and transferring polarization of optically pumped NV centers to nuclear spins outside the diamond surface. Speaker: Ish Dhand Affiliation: Ulm University, Ulm, Germany Title: Proposal for Quantum Simulation via All-Optically Generated Tensor Network States Date: 4th September, 2018 Time: 04:00 PM(Tea at 3:45 PM) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: We devise an all-optical scheme for the generation of entangled multimode photonic states encoded in temporal modes of light. The scheme employs a nonlinear down-conversion process in an optical loop to generate one- and higher-dimensional tensor network states of light. We illustrate the principle with the generation of two different classes of entangled tensor network states and report on a variational algorithm to simulate the ground-state physics of many-body systems. We demonstrate that state-of-the-art optical devices are capable of determining the ground-state properties of the spin-1/2 Heisenberg model. Finally, implementations of the scheme are demonstrated to be robust against realistic losses and mode mismatch. Speaker: Dr. Vishwanath Shukla Affiliation: Post-Doc, L'Institut de Physique de Nice (INPHYNI), Université Côte d’Azur, Nice, France. Title: Collisions of active particles in quantum fluids and quantitative estimation of effective viscosity in quantum turbulence Date: 30th August, 2018 Time: 04:00 PM(Tea at 3:45 PM) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: Particles of low velocity, traveling without dissipation in a superfluid, can interact and emit sound when they collide. We propose a minimal model in which the equations of motion of the particles, including a short-range repulsive force, are self-consistently coupled with the Gross-Pitaevskii equation. We use this model to demonstrate the existence of an effective superfluid-mediated attractive interaction between the particles; and we study numerically the collisional dynamics of particles as a function of their incident kinetic energy and the length-scale of the repulsive force. We find a transition from almost elastic to completely inelastic (sticking) collisions as the parameters are tuned. We find that aggregation and clustering result from this sticking transition in multi-particle systems. We also report our recent results on the decay of three-dimensional quantum turbulence at finite temperatures and provide a quantitative estimation of effective viscosity at finite temperatures. Speaker: Dr. Sourabh Lahiri Affiliation: BIT Mesra, Ranchi Title: Some aspects of Stochastic Thermodynamics and Quantum Random Walk Date: 27th August, 2018 Time: 04:00 PM(Tea at 3:45 PM) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: The talk would be divided into two parts. In the first half, I will provide a pedagogical introduction to Stochastic Thermodynamics (i.e., Thermodynamics applicable to systems at mesoscopic scales), followed by stating a few results that we have contributed to. The second half would involve the description of a quantum particle evolving under tight-binding Hamiltonian on a one-dimensional lattice having a detector at the origin. A method of computing the survival probability and the first detection time probability would be discussed. Speaker: Sathyanarayana Paladugu Affiliation: Kent State University Title: Tunable Electrophoresis of Colloids in Liquid Crystalline Electrolytes Date: 23th August, 2018 Time: 11:00 AM (Tea at 10:50 AM) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: Electokinetics in colloidal systems represents a broad and interesting class of out-of-equilibrium effects, caused by the external electric field that acts on spatially separated charges. Usually, the colloids are dispersed in an isotropic electrolyte such as water. In this seminar, first we discuss about many-body effects for the critical Casimir forces emerging in the presence of several colloidal particles within a critical mixture of water and 2,6-lutidine. Critical Casimir forces emerge on objects immersed in binary liquid mixtures kept near their critical (demixing) points due to the confinement of the spatial fluctuation of the local mixture composition. By taking advantage of a spatial light modulator (SLM), we generate multiple reconfigurable holographic optical tweezers (HOTs) which permit to optically trap several colloids. The forces acting on them are then determined via digital video microscopy. We first study the critical Casimir force arising between two particles as a function of their distance and then we investigate how this is affected by the presence of a third neighbouring particle. Later we discuss novel features of the dynamic out-of-equilibrium behavior of colloids when the disperse medium is an anisotropic electrolyte, namely, a nematic liquid crystal. Because of orientational order, nematics show anisotropy of properties such as electric conductivity and dielectric permittivity. When the electric field is applied to a nematic with a director that varies in space, anisotropy causes the ionic charges to separate in space. The density of space charge is proportional to the applied field, director gradients, anisotropy of conductivity and permittivity. In other words, separation of charges is defined by the properties of the liquid crystal electrolyte rather than by the properties of the solid component as in the case of isotropic electrolytes. The separated charges move in the electric field, creating electro-osmotic or electrophoretic effects with velocities proportional to the square of the electric field. We use nematic cells with photopatterned director field to illustrate the principle of the liquid crystal-enabled electrokinetics and its advantages, such as steady character of flows, control of vorticity, and the ability to transport colloidal particles of any type (solid, liquid, gaseous). We also demonstrate that the colloidal particles can be electrophoretically active even in a uniform nematic cell, provided their surface induces local dipole-like director distortions. Such a particle will move even if the electric conductivity is isotropic, being supported solely by the dielectric anisotropy. We demonstrate that the change in the sign of anisotropy causes reversal of the particle motion. Finally, we also demonstrate that the electric field can produce particle-like propagating solitary waves representing self-trapped “bullets” of oscillating molecular director. These director bullets lack fore-aft symmetry and move with very high speed perpendicularly to the electric field and to the initial alignment direction. The bullets are true solitons that preserve spatially confined shapes and survive collisions. Speaker: Dr. Juzar Thingna Affiliation: University of Luxembourg, Luxembourg Title: Nonequilibrium statistical physics: A master equation perspective Date: 20th August, 2018 Time: 04:00 PM (Tea at 3:45 PM) Venue: FB 382(Prof. Amal Raychaudhuri Seminar Room) Abstract: I will give in this talk a basic overview of the key concepts in nonequilibrium statistical physics and its connections to the theory of classical and quantum open systems described via master equations. In the first part of the talk, I’ll discuss the basics of the theory of open systems and its historical sources that can be traced back to Pauli (1928), Lindblad (1976), and others. I’ll also describe the thermodynamic framework that forms a super structure on the master equations and can be applied to systems in equilibrium and nonequilibrium. In the second part, I will briefly talk about some of the recent advances in the theory of open systems, taking three examples: i. Beyond weak system-reservoir coupling, ii. Large synchronizing networks, and iii. Finite reservoirs, and its consequences on the nonequilibrium thermodynamics. Speaker: Dr. Jayita Nayak Affiliation: University of California Davis, USA Title: Electronic structure of topological materials and quasicrystals Date: 7th August (Tuesday), 2018 Time: 11:00 AM (Tea at 10:50 AM) Venue: FB 382(Prof. Amal Raychaudhuri seminar room) Abstract: The discovery of topological materials has created tremendous attention in the scientific community and beyond because these materials can exhibit a novel state of matter in which topologically protected gapless states on their edges or surfaces are present. Such states are protected from scattering by impurities and thus have important technological applications. The rare-earth monopnictide LaBi, LaSb exhibits very large, unusual magnetoresistance which stimulates the interest in directly observing any topological surface states. Although band inversions have been postulated to induce a topological phase in LaBi but there was no experimental evidence for topological surface states in this compound. By using angle-resolved photoemission spectroscopy (ARPES) and ab-initio calculations, we have revealed the existence of topological surface states of LaBi through the observation of three Dirac cones: two coexist at the corners and one appears at the centre of the Brillouin zone. The odd number of surface Dirac cones is a direct proof of the topological nature of LaBi compound. Moreover, our ARPES measurement in conjugation with band structure calculation established the Type II Dirac semi metallic phase in PtSe2. In my recent work, six fold degeneracy has been observed at the crossing point in PdSb2 compound in contrast to Dirac and Weyl semimetals. We have used hard x-ray photoelectron spectroscopy (HAXPES) to investigate the bulk electronic structure of quasicrystals to resolve the controversy about the existence of pseudogap in these materials. The near Fermi edge (EF) spectra of Al-Pd-Mn as well as Al-Cu-Fe are strongly suppressed in intensity at EF, which provides strong evidence for the existence of the pseudogap in contrast to surface sensitive low energy photoemission spectra that shows a metallic Fermi edge. From fitting of the spectra by inverted Lorenzian function the evidence of fully formed pseudogap in Al-Cu-Fe demonstrate that the DOS at EF is zero indicating that it is close to a metal-insulator phase boundary. The existence of deeper pseudogap in bulk has been supported by the theoretical calculations. On the other hand, the HAXPES near EF spectrum of both Zn-Mg-Dy and Zn-Mg-Y exhibits shallower pseudogap compared to the Al based quasicrystals (Al-Pd-Mn and Al-Cu-Fe) that may be related to their larger carrier concentration compared to Al-Pd-Mn. Speaker: Dr. Debabrata Mishra Affiliation: Department of Physics & Astrophysics, University of Delhi Title: General Physics Seminar: Chirality Induced spin selectivity in electron transmission through self-assembled monolayers of biomolecules and its applications Date: 29th September (Thursday), 2016 Time: 2:30 PM Venue: FB 382 Abstract: In a ground breaking discovery at Weizmann Institute of Science, we have found that electrons, transmitted through helical (chiral) protein, DNA and peptides, yield spin polarized electron (up to 64% for DNA) due to the lack of inversion symmetry associated with the chiral (DNA) molecules. ‘Chirality’ in molecular systems represents structural asymmetry in which one enantiomer has “right handed” symmetry and the other “left handed”. The interaction of circularly polarized light, magnetic field or spin-polarized electrons with this chiral potential varies for the specific enantiomer and gives exciting results. I will present the discovery and development of chirality induced spin selectivity effect of self-assembled monolayers made from molecules having a helical structure, like protein (bacteriorhodopsin), dsDNA and oligopeptides of different molecular length adsorbed on Au, Ni and Al thin films. Our results indicate that helical structure promotes electron transmission and efficient spin filtering at room temperature. Interestingly, this effect could be exploited to see the spin dependent photoluminescence behavior induced by chiral protein in a hybrid semiconductor quantum dot-Protein thin film. I will also briefly discuss on some of the exciting results on spin specific chemical reactions induced by chiral dsDNA and my future research plan. Speaker: Professor Sanjoy Biswas Affiliation: Korea Institute for Advance Study Title: General Physics Seminar: Closing in on the Standard Model like Higgs boson Date: 1st March (Tuesday) Time: 4:00 PM Venue: FB 382 Abstract: The Large Hadron Collider Experiment at the CERN has discovered a Higgs-like resonance. However, the confirmation of any resemblance with the Standard Model Higgs boson requires a precise measurements of its properties and couplings with the Standard Model particles. In addition, it is also important to look for any hint of New Physics that might be associated with its production and/or decay. In this talk, I will shed some light on some of these issues. Speaker: Dr. Tanmoy Mondal Title: Vacuum stability and unitarity in Left-Right Symmetric Model Date: 25th Feb, 2016 Time: 3:00 PM Venue: FB 382 Abstract: Left-Right symmetric models are very appealing as BSM scenarios. In this talk I will discuss how theoretical constrains can be useful to restrict the LR model. Using copositivity we computed the criteria which guarantee that the vacuum is bounded from below in all directions. We examine the usefulness of the unitarity conditions which can translate into giving a stronger constraint on the model parameters together with the criteria derived from vacuum stability and perturbativity. In this light, we demonstrate the bounds on the masses of the physical scalars present in the model and find the scenario where multiple scalar modes are in the reach of Large Hadron Collider. Speaker: Professor Sei Suzuki Affiliation: Department of Liberal Arts Saitama Medical University Moroyama, Saitama 350-0495, Japan Title: Dynamics of decoherence of a qubit coupled to a spin-chain environment Date: 24th Feb, 2016 Time: 3:00 PM Venue: FB 382 Abstract: Decoherence of a quantum system is one of the important issues in quantum computation and quantum information. Controlling decoherence has been discussed recently in NMR or cold atomic experiments. We study the time dependence of the decoherence of a single spin interacting with a spin-chain environment. When the environment is close to a quantum critical point, the decoherence of a system may show a time dependence characteristic to the universality of the associated quantum critical point. In the seminar, we shall present a universal scaling theory of decoherence of a single spin when the system-environment coupling is week and the environment is slowly varied with time across a quantum critical point. Speaker: Mr. Atanu Rajak Affiliation: Saha Institute of Nuclear Physics, Kolkata Title: Statics and dynamics of topologically ordered and quenched disordered quantum many body systems Date: 25th February 2016 (Thursday) Time: 4:00 PM ( Tea will be served at 3:45 PM) Venue: FB 382 Abstract: Given the recent interest in the non-equilibrium quenching dynamics of quantum many-body systems across quantum critical points (QCPs), the studies involving quenching dynamics of a topological system across a QCP have emerged as a rapidly growing field of research. Especially, the quenching dynamics of a topological insulator and the p-wave superconductors have been explored in this connection. In the first part of this talk, I will discuss the dynamics of a Majorana edge mode in a p-wave superconducting chain following sudden and slow changes of a parameter of the Hamiltonian across QCPs. The survival probability of an edge Majorana as a function of time is studied when the system is suddenly driven from one topological phase to the other and also to the QCPs separating these phases. In the context of slow quenching dynamics of a finite p-wave superconducting chain with a complex hopping term, we ask the question whether an edge Majorana can be transported from one topological phase to the other across a gapless region. While an extensively studied NP-hard search problem of the ground state is that of the Sherrington-Kirkpatrick (SK) model. In the next part, I will speak on an interesting result that the crossover between classical (thermal) and quantum fluctuation dominated critical behaviors for the SK spin glass in transverse field occurs at a non-vanishing temperature. Speaker: Professor Janusz Gluza Affiliation: Institute of Physics, Katowice Poland Title: High Energy Physics Seminar: Techniques and tools for loop calculations. Mellin-Barnes integrals, the AMBRE package Date: 22. 02. 2016 ( Monday) Time: 4:00 PM ( Tea will be served at 3:45 PM) Venue: FB 382 Abstract: I will shortly summarize methods and software used in precise multi-loop calculations. Then I will discuss pros and cons of the Mellin-Barnes method. I will demonstrate on a couple of running examples how to use the Mathematica package AMBRE/MB (for the files see: http://prac.us.edu.pl/~gluza/ambre/). Speaker: Dr. Mayukh Ray Affiliation: Saha Institute of Nuclear Physics, Kolkata Title: CONDENSED MATTER PHYSICS SEMINAR: Influence of Martensite Transformation on the Magnetic and Transport Properties of Ni-Mn based Heusler Alloys Date: 9th February, 2016 (Tuesday) Time: 11:00 AM, Tea at 10:50 AM Venue: FB 382 (Physics Seminar Room) Abstract: The striking applicable properties and complex magnetism of Ni-Mn based Heusler alloys are mainly arises due to the first order martensite transformation (MT). Thus, it is necessary to understand the influencing factors [1]. The magnetic ground state of this dense magnetic type system giving rise to cluster spins glass state apart from its re-entrant spin glass behaviour. We will discuss it on the context of d.c and a.c magnetization and low temperature specific heat measurements [2]. The high field cooling through the irreversibility temperature finds more significant effect on the thermo-remanent magnetization (TRM) of martensite phase than the system cooled only through its martensite transformation (MT) [3]. This observation cannot be explained using the theory of kinetic arrest for first order transition. How one can induce a ferromagnetic austenite phase in place of paramagnetic austenite phase without altering the magnetic behaviour of low temperature martensite phase. I will also discuss how the martensite and austenite phase fraction across the MT influence the magneto-resistance when a magnetic field is applied. The origin of giant magneto-resistance across the MT will also be discussed [4]. References 1. Ray et al. J. Appl. Phys. 114, 123904 (2013). 2. Ray et al. Euro. Phys. Lett. 109, 47006 (2015). 3. Ray et al. J. Magn. Magn. Mater. 396, 26 (2015). 4. Ray et al. J. Phys. D: Appl. Phys. 47, 385001 (2014). Speaker: Dr. K. S. Narain Affiliation: Abdus Salam International Center for Theoretical Physics, ASICTP, Trieste, Italy Title: High Energy Physics Seminar : Physical string realization of Walcher's Topological string Date: 08. 02. 2016 (Monday) Time: 4:00 PM ( Tea will be served at 3:45 PM) Venue: FB 382 Speaker: Dr. U. Chandni Affiliation: California Institute of Technology, USA Title: General Physics Seminar: Engineering quantum transport in low dimensional electron systems Date: 1st February (Monday) 2016 Time: 11:0 AM, Tea at 10:50 PM Venue: FB 382 (Physics Seminar Room) Abstract: When electron systems are constrained to low dimensions, interactions can lead to exciting many body physics and broken symmetry states, exhibiting topological order and emergent behavior. In this talk, I will discuss electron transport in nanoscale structures consisting of two dimensional (2D) layered materials as well as one dimensional metallic nanowires. Firstly, I will discuss our efforts to engineer spin-orbit effects in graphene. This was spurred by recent theoretical predictions that heavy metal adatoms such as Indium can introduce spin-orbit coupling in graphene and lead to topological states of matter. In the second part of the talk, I will discuss our ongoing efforts in understanding electron tunneling in Van der Waals heterostructures. We employ atomically thin layers of hexagonal boron nitride as the insulating layer and metals or graphite/graphene as the counter-electrodes. Our results show strong evidence for phonon and defect mediated tunneling in such heterostructures. I will also briefly describe some of our earlier experiments on transport in ultrathin gold nanowires. We observe tunability between a non-Fermi Luttinger liquid state and a disordered state exhibiting hopping transport. In the end, I will present how these efforts can be expanded to create heterostructures of 1D and 2D materials to further explore spintronics, straintronics, tunneling and spin-orbit interactions among other phenomena. Speaker: Dr. Ishan Talukdar Affiliation: University of California, Berkley CA, USA Title: Trapped ions for quantum information processing Date: 1 February, 2015 Time: 4:00 PM (Tea at 3.45 pm) Venue: FB 382 (Physics conference room) Abstract: Laser-cooled and electromagnetically confined ions offer a quantum information processing platform with a great degree of coherence and tunability. In order to utilize such a system to solve classically hard problems, scaling to a larger computational manifold is necessary. Microfabricated surface traps promise scalability, however bringing along a new set of challenges. In this talk, after an introduction to this technology, I will discuss our efforts in understanding and tackling a source of anomalous noise in surface traps which can compromise fidelities of quantum gate operations. Speaker: Dr. Ketan Patel Affiliation: IISER Mohali Title: Anarchic Yukawas in Higher Dimensional Theories Date: 28th January (Thursday) Time: 4 pm Venue: FB 382 Abstract: Can very special pattern of fermion masses be obtained without a symmetry principle? I will try to address this question in a higher spacetime dimensional framework. An extra-dimension compactified on an orbifold generates different zero-mode profiles for fermions of different charges. Utilizing suitable scalar fields, a predictive model for fermion masses and mixing is constructed and shown to be viable with the current data. All the Yukawa couplings in the model are of order unity while the hierarchies among different fermions result from the wave-function profiles. The naturalness of anarchical Yukawa couplings and predictions for various experimentally observable parameters will be discussed. Speaker: Dr. Kush Saha Affiliation: University of California, Irvine Title: TPSC Seminar series: Interplay between electronic band topology and phonons in Dirac materials Date: 11th January, 2016 (Monday) Time: 4-5 PM (Tea 3.45 PM onwards) Venue: FB 382 Abstract: In this talk, I will discuss topological phase transition in intrinsically nontopological materials. In particular, I will show that electron-phonon interactions can induce topological phases in direct and narrow-gap Dirac insulators. The underlying mechanism for this effect can be explained in terms of the electron-phonon scattering matrix elements, which show a peculiar dependence on the sign of the mass of the Dirac fermions. A similar mechanism applies to weak Coulomb interactions and spin-independent disorder; however, the influence of these on band topology is largely independent of temperature. Finally, I will discuss the inverse of the above effect, concerning back action of the electronic band topology on the phonons. In particular, I will show that phonon linewidth may help detect the topology of the electronic bands. The underlying mechanism can again be attributed to the electron-phonon matrix elements as mentioned before. Speaker: Dr. Samir Kumar Biswas Affiliation: IIT, Hyderabad Title: Developing opto-acoustic based diagnostic devices: theory, design, optimization and patient measurement Date: 11th January, 2016 (Monday) Time: 4 pm Venue: SL215 (CELP seminar room) Abstract: Light and ultrasound transport through living tissue has been the focus of recent research in biophysics and bioengineering, mainly due to its potential application in non-destructive non-invasive diagnostic pathology. Using soft radiation like light and ultrasound, the tissue activities such as metabolism, blood flow in tissue can be quantified by correlating them with chromophores (haemoglobin, melanin, water, lipid etc). My talk will be the physics of soft matter under non-ionized radiation for tissue parameter extraction where light-tissue and ultrasound-tissue interaction will be modelled with second order partial differential equation. With advanced mathematics, physics of light and acoustic, the angiogenesis in human subjects and rat brain over a virtual domain will be reconstructed to understand the neurological problem, inflammation, arthritis progress in human inflamed joints and other possibilities such as melanoma in skin, lymph nodes inflammation etc will be the matter of discussion. Speaker: D.Venkateswarlu Affiliation: UGC-DAE Consortium for Scientific Research, Indore Title: Superconductivity in Oxy-nitrides and Skutterudites Date: 6th January 2016 (Wednesday) Time: 11 am Venue: FB-382 Abstract: Resistive broadening of Niobium Oxy-nitride samples is studied in terms of Aslamazov and Larkin (AL) theory &Lowest Landau Level (LLL) scaling for data collected down to 2K and fields upto 14T. The fluctuation dimensionality of the system is estimated from the analysis apart from other interesting parameters of interest like Ginzburg number, coherence length etc. The magnetic field induced broadening has been analysed in the TAFF (Thermally Activated Flux Flow) formalism. The activation energies of flux linesare obtained that shows a collective pinning scenario at higher magnetic fields. At low temperatures and high enough magnetic fields, a vortex glass state is observed in Niobium Oxy-nitride samples and the relevant parameters of interest are discussed. Skutterudites are relatively a new family of thermoelectric materials having promising thermoelectric properties especially due to the rattling like motion of filler atoms. The ground state of such materials is quite interesting as many of them are quite unconventional. Superconductivity in these systems is so because of the interplay between pairing and magnetism in these materials. A case study of PrPt4Ge12shows that there is a survival and existence of superconducting energy gap even after the removal of Pr down to 50 at % in PrPt4Ge12, that prelude the existence of superconductivity in an otherwise Pt4Ge12 cage as predicted by theory. Pr acts as the main stabilizing agent. A point-nodal to node-less evolution of superconducting energy gap is shown to exist as a function of Nd co-doping with Pr (up to 0.3) in Pr1-xNdxPt4Ge12 using heat capacity. Speaker: Dr Arun M. Thalapillil Affiliation: Department of Physics and Astronomy Rutgers, The State University of New Jersey Title: Probing New Physics at the LHC, Future Colliders & Yonder… Date: 5th January (Tuesday) 2016 Time: 4 PM Venue: FB-382 Abstract: The discovery of the Higgs boson has opened up new avenues to probe for physics beyond the standard model, and motivates us to revisit aspects of various models in this new light. In this talk I would like to briefly discuss three topics influenced by this - searches at the LHC & future PP-colliders for SM gauge singlet states that couple to the Higgs; supersymmetric, radiatively-generated fermion masses in the context of Higgs-fermion couplings and the muon anomalous magnetic moment; and lastly, flavor constraints on extended gauge mediation models, that accommodate large A-terms. Speaker: Dr Arun M. Thalapillil Affiliation: Department of Physics and Astronomy Rutgers, The State University of New Jersey Title: Here be Dragons - The Coming Era of Discovery at the LHC & Beyond… Date: 4th January (Monday) 2016 Time: 4 PM Venue: FB-382 Abstract: A new era has already begun with the advent of the Large Hadron Collider (LHC). Other collider and non-collider experiments, either currently running or planned for the near future, promise to shed light on some of the most intriguing questions in physics today - are there new symmetries of nature, what comprises dark matter, why is there a matter anti-matter asymmetry, what is the origin of fermion masses and so on. The Higgs boson, an excitation of the field responsible for electroweak symmetry breaking and the origin of mass, has already been discovered. A similar era of investigation into uncharted territory, at the frontier, has not existed in many decades! In this talk, I would like to briefly discuss how some of the experimental discoveries and programs specifically relating to the Higgs-like resonance have opened up new avenues, to probe and think about new physics. Speaker: Dr. Pradipta Ghosh Affiliation: Laboratoire de Physique ThÃ©orique, Orsay UniversitÃ© de Paris-Sud Title: Light singlets in supersymmetry: A glimpse beyond the Standard Model Date: 15th December, Tuesday Time: 4 PM Venue: FB-382 Abstract: Supersymmetry is a well-motivated extension beyond the standard model to overpower its shortcomings. Certain supersymmetric models contain non-minimal field content. These models can easily accommodate light neutral scalar(s) and fermion(s) in the spectrum. These light states have different novel phenomenological implications, e.g., producing unusual decay modes for the heavier standard model particles, like W Â± , Z and Higgs. An analysis of this kind is a viable alternative to probe physics beyond the standard model even when rest of the mass spectrum remains beyond the reach of the LHC. We exemplify our analysis for two non-minimal supersymmetric models with singlet superfields. Speaker: Dr. Pradipta Ghosh Affiliation: Laboratoire de Physique ThÃ©orique, Orsay, France Title: When Neutrinos meet the Collider Date: 10th December (Thursday) Time: 3:30 PM Venue: FB-382 Abstract: Experimental detection of neutrino oscillation provides firm evidence of physics beyond the standard model. Some of these new theories predict intriguing correlations between a few collider observables and the neutrino mixing angles. Measurements of these collider observables are highly envisaged during run-II of the LHC with upgraded configurations. We investigate complementary aspects of the collider and neutrino physics experiments through these correlations. We show how one can utilise these correlations to discriminate different new physics scenario. Speaker: Dr. Arijit Kundu Affiliation: Technion, Israel Title: Non-trivial Transport in Floquet Topological Insulators Date: 26th November 2015 (Thursday) Time: 4.00 PM Venue: FB-382 Abstract: Floquet topological insulators are characterized by invariant, called Bott indices, which have no equilibrium analogue. Systems with non-vanishing Bott indices may give rise to counter-intuitive transport phenomena, especially in a disordered system. For instance, the disorder can enhance the transport, in presence of certain lattice symmetry. Whereas, in certain highly disordered Floquet topological insulator, quantized charge transport can take place through edge states, where the bulk behaves as an Anderson insulator. Speaker: Dr. Arijit Kundu Affiliation: Technion, Israel Title: Topology and Transport in Periodically Driven Systems Date: 24th November 2015 (Tuesday) Time: 4.00 PM Venue: FB-382 Abstract: Topological systems in condensed matter are characterized by quantities which can only be measured non-locally. One way to introduce topological phases in certain systems is periodic driving. For example, an 1D p-wave superconductor, when driven periodically, becomes topologically non-trivial and hosts exotic steady states, which are called Floquet Majorana fermions. Whereas, graphene, under the application of circularly polarized laser is an example of Floquet topological insulator. Such topological insulators, like the quantum-hall systems, have non-trivial topology and chiral edge states which give rise to novel transport characteristics which are unique to the time-periodic systems. These systems present potential applications to various fields from quantum computation to valleytronics. Speaker: Dr. Panchanana Khuntia Affiliation: Laboratoire de Physique des Solides, Universit´e Paris-Sud 11, UMR CNRS, 91405 Orsay, France Title: NMR as a Local Probe for Magnetism and Spin Dynamics Date: 5th October 2015 (Monday) Time: 10:00 a.m.-11:00 a.m. Venue: FB-382 Abstract: I will give a brief overview of Nuclear Magnetic Resonance (NMR) and the capability of this tool in uncovering the underlying mechanism for the emergent physical phenomena such as unconventional superconductivity and phase transitions on a microscopic scale in strongly correlated electron systems. I will also present our recent results on a new frustrated quantum magnet with exotic magnetic properties. Most of the physical phenomena in correlated electron materials often elude standard theoretical paradigms, even though the properties of the individual particles that constitute these materials are well established. In many cases, understanding the novel phases and establishing a suitable model in interacting quantum systems is still an unsettled issue, which signals the frontiers of our knowledge in this field. The development of modern material synthesis method, state art of the experimental techniques, and advances in theory have reinvigorated opportunities for investigating emergent properties of quantum materials. These materials might serve as model materials for hosting exotic excitations pertinent to novel states and to test theoretical conjectures [1,2,3]. Our recent comprehensive investigation demonstrates the role of persistent spin dynamics down to T→0 induced by frustration in stabilizing the exotic spin liquid state in a novel S = 1/2 frustrated quantum magnet [4]. References [1] P. Khuntia et al., Phys. Rev. Lett. 113, 216403 (2014). [2] P. Khuntia et al., Phys. Rev. B 86, 220401(R) (2012). [3] A. K. Nayak et al., Nature Materials, 14, 679 (2015). [4] P. Khuntia et al., (submitted to Phys. Rev. Lett.). Speaker: Jyotirmoy Bhattacharya Affiliation: Department of Mathematical Sciences, Durham University, UK. Title: Constraints on hydrodynamic transport phenomena from equilibrium partition functions. Date: 23rd September 2015 (Wednesday) Time: 4 PM Venue: FB-382 Abstract: We will discuss the equilibrium thermal partition function for quantum field theories on arbitrary stationary background spacetime, in the long wavelength expansion. We shall first consider space-filling fluids and demonstrate that the equations of relativistic hydrodynamics are significantly constrained by the requirement of consistency with such a partition function. In this case, these constraints coincide precisely with the relations between transport coefficients that follow from the second law of thermodynamics. We will then use the power of this partition function formalism, to study and constrain the surface transport properties of fluids. Speaker: Jyotirmoy Bhattacharya Affiliation: Department of Mathematical Sciences, Durham University, UK. Title: Geometric aspects of quantum entanglement Date: 22nd September 2015 (Tuesday) Time: 4 PM Venue: FB-382 Abstract: We shall begin with a brief introduction to the basic concepts behind the gauge-gravity duality. In this context, we will go on to describe how the notion of entanglement entropy in quantum field theory, acquires a geometrical interpretation. Using such geometric techniques, we will explore some interesting properties of entanglement entropy, which has close resemblance with thermodynamics laws. We will then speculate on how these properties may be helpful to recast gravitational dynamics as an effective dynamics of quantum entanglement, via the gague-gravity duality Speaker: Hilal Ahmed Affiliation: AMU, Aligarh Title: Synthesis and Characterization of Nanocrystalline ColossalMagnetoresistive Manganites Date: 13th February 2015 (Friday) Time: 11 am Venue: FB-382 Abstract: In this talk, I shall present results obtained on nanocrystalline Sr-doped LaMnO3. The parent material LaMnO3 is an antiferromagnetic insulator at room temperature. Strontium (Sr) doped LaMnO3 is an interesting manganite which shows ferromagnetism at room temperature with a rich phase diagram. These materials are well suited for spintronics and biomedical applications Speaker: Hilal Ahmed Affiliation: AMU, Aligarh Title: Synthesis and Characterization of Nanocrystalline ColossalMagnetoresistive Manganites Date: 13th February 2015 (Friday) Time: 11 am Venue: FB-382 Abstract: In this talk, I shall present results obtained on nanocrystalline Sr-doped LaMnO3. The parent material LaMnO3 is an antiferromagnetic insulator at room temperature. Strontium (Sr) doped LaMnO3 is an interesting manganite which shows ferromagnetism at room temperature with a rich phase diagram. These materials are well suited for spintronics and biomedical applications Speaker: Hilal Ahmed Affiliation: AMU, Aligarh Title: Synthesis and Characterization of Nanocrystalline ColossalMagnetoresistive Manganites Date: 13th February 2015 (Friday) Time: 11 am Venue: FB-382 Abstract: In this talk, I shall present results obtained on nanocrystalline Sr-doped LaMnO3. The parent material LaMnO3 is an antiferromagnetic insulator at room temperature. Strontium (Sr) doped LaMnO3 is an interesting manganite which shows ferromagnetism at room temperature with a rich phase diagram. These materials are well suited for spintronics and biomedical applications Speaker: Hilal Ahmed Affiliation: AMU, Aligarh Title: Synthesis and Characterization of Nanocrystalline ColossalMagnetoresistive Manganites Date: 13th February 2015 (Friday) Time: 11 am Venue: FB-382 Abstract: In this talk, I shall present results obtained on nanocrystalline Sr-doped LaMnO3. The parent material LaMnO3 is an antiferromagnetic insulator at room temperature. Strontium (Sr) doped LaMnO3 is an interesting manganite which shows ferromagnetism at room temperature with a rich phase diagram. These materials are well suited for spintronics and biomedical applications Speaker: Hilal Ahmed Affiliation: AMU, Aligarh Title: Synthesis and Characterization of Nanocrystalline ColossalMagnetoresistive Manganites Date: 13th February 2015 (Friday) Time: 11 am Venue: FB-382 Abstract: In this talk, I shall present results obtained on nanocrystalline Sr-doped LaMnO3. The parent material LaMnO3 is an antiferromagnetic insulator at room temperature. Strontium (Sr) doped LaMnO3 is an interesting manganite which shows ferromagnetism at room temperature with a rich phase diagram. These materials are well suited for spintronics and biomedical applications Speaker: Prof. A. P. Baburaj Affiliation: IIT Madras Title: The boundary layer velocity field in turbulent convection Date: 25th April, 2015 (Saturday) Time: 11 am Venue: Old core lab 103E Abstract: We measure the spatial velocity field in a horizontal plane within the velocity boundary layer over the horizontal hot plate in turbulent convection in water for 105 Ra 109 and Pr around 5. A new criterion is used to detect the coherent structures, namely line plumes, from this velocity field. The velocity field mostly shows four types of flow patterns, we present the PDF of velocities for each patterns to show their differences. The instantaneous velocity distributions match with that of laminar natural convection boundary layers, with the regions far away from plumes being affected by the external shear at the larger Ra. The mean velocity fields show no clear patterns and the fluctuating velocity fields show velocity field devoid of the mean shear, i.e. the pattern of flow driven by the plumes alone. The PDF of velocities of the plumes and the fluctuating components of the flow velocities coincide implying that plumes mostly contribute to the fluctuating velocity field. The joint PDF of horizontal and vertical instantaneous velocities show an 'arrow' type structure with the arms of the arrow head showing plume and boundary layers while the arrow shaft showing shear affected regions. The spectra of instantaneous velocities show a Bolgiano-Obukhov scaling at larger wave numbers while it shows a -1 scaling for lower wave numbers; we show that the -1 scaling is from regions affected by shear. Speaker: Dr. Srimanta Middey Affiliation: Department of Physics, University of Arkansas, USA Title: Heterointerface Engineering of Correlated Oxides Date: 14th April 2015 (Tuesday) Time: 4 PM Venue: FB-382 Abstract: Periodic geometrical arrangement of the constituent atoms in a crystalline solid is the backbone of electronic and magnetic properties. The alternation of this atomic arrangement, by creating interface between two chemically, electronically and structurally dissimilar materials can be expected to result a set of many-body states, which are unattainable in the constituent bulk materials. As the strong intercoupling among spin, charge, orbital, lattice degrees of freedom in correlated oxides promote various fascinating collective phenomena (e.g. superconductivity, magnetism, ferrolectricity ...), the additional broken symmetries and frustrated couplings across interface may give rise to a new horizon to novel electronic, magnetic and topological states. However, microscopic understanding of such interfacial properties is a grand challenge and it requires various advanced techniques. In this talk, I will illustrate the success in creating `new’ electronic states by growing transition metal oxide superlattices with unit cell precision. The implementation of synchrotron diffraction, x-ray absorption spectroscopy, resonant x-ray scattering experiments to elucidate the response of the underlying structures, spins, orbitals and charges due to this heterostructuring will be also discussed. Additionally, I will present the prospect of such engineered heterointerfaces for energy harvesting and application as next generation materials for Mott electronics. Speaker: Auditya Sharma Affiliation: Tel Aviv University, Israel Title: Landauer current and mutual information Date: 14th April, 2015 Time: 2.30 PM Venue: FB-382 Abstract: We study quantum evolution of the density matrix of a quantum dot con- nected to left and right leads initially maintained at chemical potentials µL and µR respectively and temperature T, within the non-interacting resonant-level model. The full nonequilirbium mixed state density matrix of the whole system is written down exactly, and the mutual information of the dot with respect to the leads is computed. A strong and direct correlation is found between the Landauer current, and the mutual information at all times, the steady-state values in particular displaying a quadratic relationship at high temperatures. We argue that this relationship could potentially be exploited experimentally to ‘measure’ mutual information. I will try to give an elementary introduction and build up the technical details gradually.References: [1] Auditya Sharma and Eran Rabani. Phys.Rev.B 91, 085121 (2015). Speaker: Gagan Kumar Affiliation: IIT Guwahati Title: Terahertz Plasmonic Waveguides Date: 9-April-2015 (Thursday) Time: 3 PM Venue: FB-382 Abstract: Plasmonic metamaterials have the ability to facilitate the next generation miniaturized high speed communication devices and networks. In my talk, I will discuss about the design, fabrication and characterization of the terahertz guided wave devices on the planar surfaces using plasmonic metamaterials. Thin metal films when periodically corrugated with subwavelength scale structures forms a plasmonic waveguide, which can result in the propagation of terahertz modes confined in both the transverse directions. The degree of confinement and frequency of the resonant modes can be controlled with the geometrical parameters of the structures. In my talk, I will also discuss about the possibly of replacing metals substrates with semiconductors for such waveguide which can be advantageous in making active components. Speaker: Dr. R. Prabhu Affiliation: HRI, Allahabad Title: Multipartite quantum correlations in many-body systems. Date: 8th April, 2015 (Wednesday) Time: 4 PM Venue: FB-382 Abstract: The cross-braiding between quantum information and condensed matter physics has recently stimulated excitation among researchers. Many-body systems are potential physical substrates to realize several quantum information protocols. The tools developed in quantum information have been put to use in analyzing collective phenomena in many-body systems. Many-body systems have been studied by observing, for example, their response to external perturbations, various order parameters, and excitation spectra. In this talk, I will characterize the behavior of several quantum correlation measures, including bipartite and multipartite ones, in spin models like Heisenberg spin system, XY-spin chain, etc. Also, I deal with the characterization of multipartite quantum correlation in spin models which can be both clean and disordered ones. Speaker: Dr. Arijit Kundu Affiliation: IU Bloomington, IN, US Title: Topology and Transport in Periodically Driven Systems Date: 31st March, 2015 (Tuesday) Time: 4 PM Venue: FB-382 Abstract: One way to introduce topological phases in certain systems is periodic driving. For example, an 1D p-wave superconductor, driven periodically, can go through a Floquet transition to become topologically non-trivial. Such Floquet topological superconductor can host exotic steady states, which are called Floquet Majorana fermions. Whereas, graphene, under the application of circularly polarized laser is an example of Floquet topological insulator. Such topological insulators, like the quantum-hall systems, have non-trivial topology and chiral edge states. Such systems present potential applications to various fields from quantum computation to valleytronics. In this talk I'll present our recent works on topological classification and some novel transport characteristics of such driven systems. Speaker: Dr. Veeresh Singh Affiliation: University of KwaZulu-Natal Durban, South Africa Title: Unveiling the population of distant radio galaxies and their environments Date: 31st March, 2015 (Tuesday) Time: 12 noon Venue: FB-382 Abstract: Radio galaxies exhibit jet-lobe radio structures emanating from active nucleus and are found to be hosted in massive elliptical galaxies. Radio galaxies particularly at higher redshifts and in obscured environments can be used as beacon to identify active galaxies and understand their evolution. It has been shown that Ultra Steep Spectrum (USS) radio sources are one of the efficient tracers of powerful High-z Radio Galaxies (HzRGs). We study properties of a USS sample derived from deep 325 MHz and 1.4 GHz observations and find a substantial population of unexplored weaker radio galaxies potentially hosted in obscured environments along with the population powerful HzRGs. Furthermore, in general, powerful HzRGs tend to reside in (proto)cluster environments. Speaker: Dr. Debakanta Samal Affiliation: Max-Planck Institute, Munich, Germany Title: Tailoring the electronic properties of cuprate layers on unit cell level: A boost towards designing artificial high Tc cuprates. Date: 26th February, 2015 (Thursday) Time: 4.30 PM Venue: FB-382 Speaker: Dr. Dinesh Narayana Naik Affiliation: Department of Physics, Mehsana Urban Institute of Sciences, Ganpat University Title: Correlation holography: A marriage of holography with statistical optics Date: 25th February, 2015 (Wednesday) Time: 4 PM Venue: FB-382 Abstract: With unconventional holographic techniques incoherent holography, coherence holography and photon correlation holography, it is possible to record and reconstruct 3-D objects as the second or fourth order correlation function of the optical fields. Unlike conventional holography, these techniques require only incoherent light for the illumination. The reconstructed object manifests itself in the spatial coherence function of the optical field. As a consequence, we can extend the holographic imaging to phenomena such as fluorescence with possible biomedical applications. Moreover, optical fields with a desired spatial coherence function can be synthesized using the technique of coherence holography with possible applications to microscopy and lithography. Speaker: Dr. Vishwanath Shukla Affiliation: IISc, Bangalore Title: Particles And Fields In Superfluids: Insights From The Two-Dimensional Gross-Pitaevskii Equation. Date: 23th February 2015 (Monday) Time: 4 PM Venue: FB-382 Abstract: We study the dynamics of active particles in two-dimensional superfluids at temperature T = 0, for a variety of initial configurations, by carrying out extensive direct-numerical-simulations of the two-dimensional, Galerkin-truncated Gross-Pitaevskii equation. Our study elucidates the interplay of particles and fields, in both simple and turbulent flows. We show that particle collisions can be inelastic, if the repulsive interactions between particles is weak, and elastic otherwise. We show that assemblies of many particles and vortices yield turbulent spatiotemporal evolutions. Speaker: Hilal Ahmed Affiliation: AMU, Aligarh Title: Synthesis and Characterization of Nanocrystalline ColossalMagnetoresistive Manganites Date: 13th February 2015 (Friday) Time: 11 am Venue: FB-382 Abstract: In this talk, I shall present results obtained on nanocrystalline Sr-doped LaMnO3. The parent material LaMnO3 is an antiferromagnetic insulator at room temperature. Strontium (Sr) doped LaMnO3 is an interesting manganite which shows ferromagnetism at room temperature with a rich phase diagram. These materials are well suited for spintronics and biomedical applications Speaker: Dr. Debi Prasad Datta Affiliation: Institute of Physics (IoP), Bhubaneshwar Title: Ion beam induced synthesis and modifications of nano structures:Fundamentals and some applications. Date: 14th January, 2015 (Wednesday) Time: 12 pm Venue: FB-382 Abstract: Ion bombardment of solids is an efficient route towards processing of nano-scale surface patterns as well as synthesis and modification of nanostructures. Ion-beam-patterned surfaces are receiving increasing interest due to their promising applications, e.g., as templates for growing thin films with tailored properties. In this talk, I shall present our experimental investigations on the evolution of surfaces under off-normally incident medium energy ion bombardment. In fact, I shall show that ripple pattern evolution on Si[1], Ge[2], or SiO2 can be understood in a common theoretical framework, viz. as a result of ion erosion and ion induced mass redistribution. Irradiation-induced transition of such sinusoidal ripple patterns to a saw-toothed one will be demonstrated, which will be correlated to slope-dependent non-linear effect and shadowing of the incident ion beam. On the other hand, similar off-normal ion bombardment will be shown to result in no surface patterning but development of a porous structure containing nanofibers in case of GaSb and InSb [3], owing to growth of voids during bombardment. Some properties of such ion-induced structures, like photoluminescence, antireflection and hydrophobicity, will be discussed. In the last part of the talk, I shall describe studies on synthesis and modification of embedded Au nanoparticles in SiO2 by MeV Au2+-ion bombardment [4]. 1. D. P. Datta et al., Phys. ReV. B 69, 235313 (2004); Phys. Rev. B 71, 235308 (2005); Phys. Rev. B 76, 075323 (2007), S. K. Garg and D. P. Dattaet al., Appl. Surf. Sci. 310, 147 (2014); Appl. Surf. Sci. 317, 476 (2014).2. D. P. Datta et al., (to be communicated to Phys. Rev. B).3. D. P. Datta et al., J. Appl. Phys. 115, 123515 (2014); Applied Surface Science 310, 189 (2014); J. Appl. Phys, 116, 033514 (2014); J. Appl. Phys. 116, 143502 (2014). 4. D. P Datta et al., Appl. Surf. Sci. 310, 164 (2014). Speaker: Faraz Ahmed Inam Affiliation: Dept. of Physics, Aligarh Muslim Universiuty Title: Fundamental characterisation of nanodiamond nitrogen-vacancy (NV) centres spontaneous emission as a single photon source. Date: 06 January 2015 (Tuesday) Time: 3 pm Venue: FB - 382 Abstract: With its inbuilt, unique spin and optical properties, negatively charged nitrogen-vacancy (NV) centres in diamond have attracted wide interest in interdisciplinary research fields, ranging from quantum technologies, high-resolution magnetometry to biomedical imaging and tracking. Most of the highly sensitive applications of diamond-NV centers in the above fields rely on bright, controllable and photo-stable NV luminescence from very small diamond nanocrystals. Nanodiamond NV centre has been widely studied in the past decade and significant enhancements in its emission rate and capture factors were achieved. Nevertheless a complete picture of its spontaneous emission under the influence of the local electromagnetic nano-environment was non-existent at the beginning of my research study. In my research, I sought to improve the understanding of NV emission by systematically isolating the various individual mechanisms influencing its emission.In this talk, I will shows how the systematic approach of our study of nano diamond NV emission under a range of conditions and environments elped us to develop and contribute towards the evolved understanding ofits spontaneous emission. Speaker: Dr. Swapnil Patil Affiliation: Tata Institute of Fundamental Research (TIFR) Title: Photoemission insight into exotic low temperature physics ofrare-earth intermetallics: heavy-fermion behaviour, mixed valency,Kondo physics etc. Date: 6th January, 2015 (Tuesday) Time: 12 pm Venue: FB - 382 Abstract: In this talk, I shall present the results of photoemission studies of remarkable Ce- and Yb- based materials, exhibiting unique properties like Kondo physics, heavy-fermion behaviour, and mixed valency. One of the important problems in correlated electron systems concerns the observation of "large-small" Fermi surface transition in Kondo systems with temperature. It is believed that the Fermi surface of a Kondo system expands at lower temperatures due to the formation of many-body Kondo singlet states. Our photoemission results however demonstrate temperature invariant Fermi surface in a prototypical Kondo system, YbRh2Si2. Additionally our results on Ce-Kondo systems demonstrate electronic spectral evolution which deviates from the predictions of Anderson model, a theoretical model normally used to interpret photoemission spectra from Kondo systems. Potential candidates to explain these discrepancies will be briefly discussed. Finally Fermi surface studies on YbCo2Si2, a stable valent Kondo lattice, will be discussed which serves as a reference compound for YbRh2Si2, which happens to be close to quantum criticality.

 Speaker: Dr. Sunil Kumar Affiliation: Weizmann Institute of Science, Israel Title: Contolled multiphoton micro-spectroscopy for high resolution imaging applications. Date: 22nd October, 2014 (Wednesday) Time: 11 am Venue: FB-382 Speaker: Dr. Sita Sunder Affiliation: Postdoc in Physics, IIT Kanpur Title: Flow shear driven instability in EMHD Date: 16 September 2014 Time: 4 pm Venue: Old corelab 103E Meeting Room Speaker: Sriram Guddala Affiliation: Metamaterials & Plasmonics Lab, Department of Physics, IIT Kanpur Title: Metal-Dielectric Periodic Photonic Structures Date: 27 August 2014 (Wednesday) Time: 3 pm Venue: FB - 382 Abstract: The optical field confinement in periodic metal-dielectric photonic structures has been of great interest to achieve intense localized electric field strengths due to unified properties driven from plasmonic properties of metallic nanostructures and photonic band gap properties of periodic dielectric structures [1]. Here, the metal-dielectric photonic crystals (MDPCs) and some preliminary results on metamaterial perfect optical absorbers be discussed. In the context of MDPCs, it will be shown that the confined optical fields resulted from redistributed photon density of states and their influence on enhancement of Raman scattering in metal nanoparticles impinged 3D (inverse opal structures) and 1D (multilayered microcavity) photonic crystals [2-3] . The intense optical fields are obtained on excitation of band edge (3D opals) and defect state (1D microcavity) photonic modes of photonic band gap structures and their coupling to the surface plasmon resonance properties of impinged metal nanoparticles. These intense optical fields were further probed by performing spectral and angle resolved surface enhanced Raman scattering (SERS) studies, and the enhancement of Raman scattering is understood through a novel photon-plasmon-phonon interaction mechanism. Our studies show a novel aspect of PBG influence to accomplish a highly reliable periodic metal-dielectric SERS substrate for sensing and photonic applications. At the end it will be discussed some of the recent studies on design, fabrication and characterization of novel architectures of multilayer metal-dielectric perfect optical absorbers for visible and NIR wavelengths. References: [1] S. Guddala, K. Shadak Alee, and D. Narayana Rao, "Fabrication of multifunctional SnO2 and SiO2-SnO2 inverse opal structures with prominent photonic band gap properties," Opt. Mater. Express 3, 407-417 (2013). [2] S. Guddala, V. K. Dwivedi, G. Vijaya Prakash and D. Narayana Rao, "Raman scattering enhancement in photon-plasmon resonance mediated metal-dielectric microcavity," Journal of Applied Physics, 114, 224309 (2013). [3] S. Guddala, K. S. Alee, A. Chiappini, M. Ferrari, and D. Narayana Rao, "Experimental investigation of photonic band gap influence on enhancement of Raman-scattering", Journal of Applied Physics, 112, 084303 (2012). Speaker: Dr. Ipsita Mandal Affiliation: Perimeter, Waterloo Title: Low Energy Physics of a Non-Fermi Liquid System Date: 20 August 2014 Time: 3 pm Venue: FB - 382 Abstract: We devise a renormalization group analysis for quantum field theories with Fermi surface to study scaling behaviour of non-Fermi liquid states in a controlled approximation. The non-Fermi liquid fixed points are identified from a Fermi surface in (m+1) spatial dimensions, while the co-dimension of Fermi surface is also extended to a generic value. We also study superconducting instability in such systems as a function of dimension and co-dimension of the Fermi surface. The key point in this whole analysis is that unlike in relativistic QFT, the Fermi momentum kF enters as a dimensionful parameter, thus modifying the naive scaling arguments. The effective coupling constants are found to be combinations of the original coupling constants and kF.

 Speaker: Prof. Sayan Kar Affiliation: IIT Kharagpu Title: Eddington-inspired Born-Infeld gravity Date: 27th March 2014, Thursday Time: 4 pm Venue: FB - 382
 Speaker: Dr. Sinu Mathew Affiliation: NUSNNI-NanoCore and Dept. of Electrical and Computer Engineering, National University of Singapore Title: The Effects of MeV Proton Irradiation on Interface Two-Dimensional Electron Gas (LaAlO3/SrTiO3) and Layered Solids (MoS2,graphene) Date: 3rd March 2014, Monday Time: 12:00 pm - 1:00 pm. Venue: FB - 382 Abstract: The two-dimensional electron gas (2DEG) formed at the interface between two band insulators LaAlO3 (LAO) and SrTiO3 (STO) is one of the most fascinating systems in the field of oxide research. Tailoring of the conductivity of this interface 2DEG is a challenge for the practical applications of this system. MeV Proton irradiation on LAO/STO system is found to manipulate interfacial conductivity by carrier localization and eventually producing an insulating ground state by tailoring the defect structure of the substrate STO. The results of electrical and magneto-transport, Raman spectroscopy and spectroscopic ellipsometry will be discussed[1]. The second part of the talk will be on the effects of MeV Proton irradiation on Molybdenum disulphide and graphene. MoS2 a diamagnetic layered solid, is found to show ferrimagnetic ordering at room temperature when exposed to 2 MeV proton beam[2]. A disorder mode corresponding to a zone-edge phonon and a valency of Mo higher than +4 have been detected in the irradiated samples. The stability of supported and suspended graphene under MeV Proton irradiation will also be discussed[3]. References S. Mathew, A. Annadi, T.K. Chan, Teguh Citra Asmara, D. Zhan, Ariando, A. Rusydi, Z.X Shen, M.B.H. Breese and T. Venkatesan. ACS Nano 7 (2013) 10572 S. Mathew, K. Gopinadhan , T.K. Chan, X.J. Yu, D. Zhan, L. Cao, A. Rusydi, M.B.H. Breese, S. Mathew, T.K. Chan, D. Zhan, K. Gopinadhan, A.R. Barman, M.B.H. Breese, S. Dhar, Z.X. Shen, T.Venkatesan and John TL Thong. Carbon 49 (2011) 1720; J. Appl. Phys. 110 (2011) 84309
 Speaker: P. Santhana Raman (Post-doctoral fellow at Institute of Physics, Bhubaneswar) Affiliation: Centre for Ion Beam Applications, Department of Physics, National University of Singapore, Singapore Title: Research and Development with Energetic Broad- and Nano- Ion Beams:From Ion Beam Analysis to Novel Materials Modification and Proton Beam Writing Systems Date: 24th February, 2014 (Monday) Time: 3:30 pm - 4:30 pm. Venue: FB - 382 Abstract: The process that can be accomplished using energetic ion beam technique broadens itself with no limit. Starting from routine materials analysis (via various Ion beam analysis technique), the advent of ion beam extends to carve and alter structures at nano scale, with nano-sized ion beam, to form novel materials. The cause and the effect of these energetic ion beams on both materials and soft-tissues are of paramount importance in understanding it in terms of both fundamental and application point of view. This talk will cover the Ion beam analysis techniques that were crucial in novel materials synthesis (especially with embedded InN and ZnO nanoclustres in silica matrix). The systematic approach, using energetic ion beams, in producing surface patterns will be discussed in the light of basic physics and its applications. Later in the talk I will introduce and explain about the next generation lithographic technique, namely Proton Beam Writing and its capability to produce high aspect ratio nanostructures. The developmental activities involved in making of high brightness ion source, to be used in next generation compact proton beam lithography, with a promise to deliver sub-10 nm beam spot size, will also be discussed.
 Speaker: Dr. Haraprasanna Lenka (Post-doctoral fellow at Institute of Physics, Bhubaneswar) Title: Microscopic characterization of GaN heterostructures using RBS/C and TEM: A comparative study. Date: January 16th, 2014 (Thursday) Time: 4:00 pm - 5:00 pm. Venue: FB - 382 Abstract: Recently, the success of the growth of high quality c-GaN layers on Si substrate has attracted considerable academic and commercial interest, because it can facilitate the integration of microelectronics and optoelectronics. But the large lattice and thermal mismatch between GaN and Si introduces a lot of dislocations which pose a major obstacle in the production of defect-free layers, much needed for device applications. Hence, material processing requires intermediate monitoring to quantitatively track the amount of defects formed during growth. Apart from measuring the critical characteristics like the dislocation density, a good estimation of strain and composition is also important for device optimization. To meet this challenge, ion channeling is a very attractive and a powerful technique because of its unique mass sensitivity to the type of defects separately (such as point defects, dislocations, stacking faults or defect clusters). Results of RBS/C will be presented as a fast and non-destructive technique to analyze the defect density and the elastic strain, two parameters which can potentially affect the device performance in comparison with TEM results.
 Speaker: Debanjan Chowdhury (Harvard University) Title: Unconventional phases of quantum matter Date: January 15th, 2014 (Wednesday) Time: 11:00 am - 12:00 pm. Venue: FB - 382 Abstract: Theorists have been studying unconventional states of quantum matter over the past few years and starting recently, experiments on such states have finally appeared, generating much excitement. I will describe experimental observations on high temperature superconductors and magnetic insulators and their influence on our theoretical understanding. In the first part of the talk, I will introduce the theory of quantum criticality in metals and apply it to the phase diagrams of the high temperature superconductors. I'll review some of the experiments on the iron pnictides, which point toward the possible existence of a quantum critical point underneath the superconducting dome and try to offer a partial explanation for some of the mysterious observations[1]. In the second part of the talk, I'll review some recent experiments on a kagome lattice anti-ferromagnet and argue that many of the observed features can be explained by the presence of fractionalized excitations in a quantum spin liquid[2]. [1] D. Chowdhury, B. Swingle, E. Berg and S. Sachdev, Phys. Rev. Lett. 111, 157004 (2013). [2] M. Punk, D. Chowdhury and S. Sachdev, Nature Phys. (to appear), 2014; arXiv:1308.2222.
 Speaker: Dr. Sanjay Kumar Mandal (NIT Agartala) Title: Multiferroic Composites for Magnetic Field Sensors. Date: December 9th, 2013 Time: 11:30 am - 12:30 pm. Venue: FB - 382 Abstract: Multiferroics with two or more ferroic (ferroelectric, ferro/ferri/anti-ferromagnetic, ferroelastic) orderings have attracted considerable attention in recent years. Single-phase multiferroics are rare and their magnetoelectric (ME) responses are either weak or occur at temperatures too low for practical applications. Ferromagnetic-piezoelectric composites, however, show strong ME coupling at ambient temperatures. The ME effect is a property mediated by elastic deformation. The composites show a rich variety of phenomena including giant low-frequency ME interactions. This presentation will focus on recent developments in the physics and applications of composite multiferroics. The discussion will include our work on functionally graded composites for use as ultra sensitive magnetic field sensors.
 Speaker: Dr. Aditya Kelkar (TIFR, Mumbai) Title: Ion collisions with molecules and Clusters Date: January 8th, 2014 (Wednesday) Time: 4:00 pm - 5:00 pm. Venue: FB - 382 Abstract: The description of the temporal and spatial evolution of systems of mutually interacting particles is of fundamental importance in atomic collision physics. Theoretically the difficulty of this task lies in the fact that the Schrödinger equation is not analytically solvable for more than two particle systems even when the underlying forces are precisely known. On the other hand collisions with photons and charged particles (electrons and heavy ions) have proved to be excellent tools to investigate the structural and dynamical properties of physical systems like atoms, molecules, clusters and solid surfaces etc. The dynamics can be studied in a wide range of Coulomb interaction strength and time scales by suitable choice of heavy ion beams, offering the opportunity to study a multitude of processes such as ionization and capture, radiative and non-radiative relaxation etc to coherence effects and collective behaviour in many body systems as well as bond formation and rearrangement in chemical reactions. In this talk I shall discuss the interaction of heavy ions with many body systems taking two examples from my research work. In the first part, I will describe collisions of highly charged heavy ions with fullerene C60 in the intermediate velocity (vp ~ 10 a.u.) range, focusing on the excitation of a collective surface plasmon mode known as Giant dipole plasmon resonance or GDPR. In this velocity range the dwell time of the projectile ion is ~10-17 seconds and the interaction can be treated in the perturbative regime. However, in collisions at very low energy (vp ~ 0.01 a.u.) the interacting particles have sufficient time for electronic rearrangement and bond formation leading to chemical reactions. In particular I will discuss the dynamics of a bimolecular nucleophilic substitution reaction between F - (anion) and CH3Cl in gas phase using velocity map imaging (VMI) technique.
 Speaker: Dr. Arijit Saha (University of Basel, Switzerland) Title: Novel Transport phenomena in hybrid junctions of Nanowires Date: January 7th, 2014 (Friday) Time: 2:45 pm - 3:45 pm. Venue: FB - 382 Abstract: In the first part of the talk I shall give a brief introduction to my field of research called "Mesoscale and Nanoscale Physics" highlighting the subfield of low dimensional systems with examples and experiments. In the next part, I shall talk about transport properties of hybrid superconducting junctions of one dimensional n a no wi r es (NW). In particular, I shall demonstrate possible scenarios for production of pure spin current through such junctions. I shall also show that (a) effects due to inclusion of electron-electron interaction induced back-scattering in the wire, and (b) competition between the charge transport via the electron and hole channels across the junction give rise to a non monotonic behavior of the sub gap conductance as a function of temperature. ln the last part of the talk I shall introduce NW in the presence of Rashba spin orbit interaction, uniform magnetic field, and spatially modulated magnetic field. Such fully gapped system can support fractional fermion (FF) bound states at the two ends of the NW. I shall discuss the transport and noise signatures of such FF bound states which has never been investigated so far in literature.
 Speaker: Dr. Jaivardhan Sinha (National Institute for Materials Science (NIMS), Tsukuba, Japan) Title: Perpendicular magnetic anisotropy and current induced effective field in Ta(N)|CoFeB|MgO Date: December 6th, 2013 Time: 12:00 pm - 01:00 pm. Venue: FB - 382 Abstract: Perpendicular magnetic anisotropy (PMA) originating from the interface in Heavy metal(Pt, Ta)|Ferromagnet(Co, CoFeB)|Oxide structure (Al2O3, MgO) is of great interest because of its potential application in spintronics based devices. The recent finding of spin-orbit torque (spin Hall spin torque) in these heterostructures [1,2] has increased its significance manifold as it allows one to manipulate magnetization direction using in-plane current. Solid understanding the role of Heavymetal|Ferromagnet interface and Ferromagnet|Oxide interface is essential for utilizing them in application. In this talk I shall discuss the Ta|CoFeB interface properties in Ta(N)|CoFeB|MgO and the current induced effective field likely generated due to spin Hall effect from Ta. In general, Ta is known for creating a magnetic dead layer when placed next to a magnetic layer. As the CoFeB layer thickness is of the order of 1 nm to obtain PMA, thus it is desirable to have negligible magnetic dead layer from the point of view of thermal stability. The effect of Nitrogen doping in Ta underlayer on interface anisotropy, magnetic dead layer thickness and current induced effective field will be also discussed [3]. References: [1] Junyeon Kim, Jaivardhan Sinha, Masamitsu Hayashi, M. Yamanauchi, S. Fukami, T. Suzuki, S. Mitani and Hideo Ohno, Nature. Materials. 12, 240 (2013).[2] L. Liu, C. F. Pai, Y. Li, H. W. Tseng, D. C Ralph, and R. A. Buhrman, Science 336, 555 (2012). [3] Jaivardhan Sinha et al, Appl. Phys. Lett. 102, 242505 (2013).
 Speaker: Dr. Shibabrata Nandi (Jülich Centre for Neutron Science & Peter Grünberg Institute) Title: Structure, magnetism and superconductivity in Fe-based superconductors Date: November 27th, 2013 Time: 11:30 am - 12:30 pm. Venue: L8 (LHC) Abstract: In iron-based high-temperature superconductors, magnetic fluctuations and magneto-elastic effects are believed to be important for the superconducting electron pairing mechanism. To gain insight into the interplay between the different ordering phenomena and the underlying couplings we studied the magnetic order and lattice distortion on AFe2As2 (A = Ca, Sr, Ba, Eu) single crystals by neutron and x-ray diffraction. High-resolution x-ray diffraction and neutron scattering measurements reveal an unusually strong response of the lattice and ordered magnetic moment to superconductivity in Co-doped BaFe2As2 . We propose that the coupling between lattice and superconductivity is indirect and arises due to the magnetoelastic coupling, in the form of emergent nematic order, and the strong competition between the magnetism and superconductivity. For the P-doped EuFe2As2 , coexistence between the ferromagnetism and superconductivity was observed and explained in terms of formation of a spontaneous vortex state.
 Speaker: Dr. Ajay Soni (School of Basic Sciences, IIT Mandi, Himachal Pradesh) Title: Nanocomposites of Layered Chalogenides for Thermoelectric Applications Date: November 26th, 2013 Time: 12:15 Pm - 1:15 pm. Venue: L9 (LHC) Abstract: Research in the field of thermoelectricity (TE) is full of outstanding ideas, the materials having properties of an electron-crystal-phonon-glass, such as rattling semiconductors, alloys, heterostructures, and bulk-nanocomposites have shown to be efficient TE materials. In this context, the nanocomposites of layered chalcogenides (Te and Se) and pnictogen (Bi and Sb) materials have been preferably studied for their high-performance TE properties arising due to layered structure and narrow band gap.1 The efficiency of the TE material is quantified by a dimensionless thermoelectric figure of merit, $ZT = S^2\sigmaT/\kappa$, where S is the Seebeck coefficient, $\sigma$ is the electrical conductivity, $\kappa$ is the thermal conductivity and T absolute temperature. Thus the interplay of the three physical parameters makes the problem very complex for TE materials. The research talk will focus on a novel class of solution grown Bi2Te3-xSex nanoplatelet composites (NPCs) having an enhanced thermoelectric properties2 , and the effects of the thermodynamic environment during spark plasma sintering.3For the case of NPCs, the grain boundaries and interfaces are playing important role such that the charge carriers and phonons couple in a unique fashion. The subtle understanding of the interface crystallization, grain growth and filtering of electron and phonons will be discussed. A brief notion on the family of layered materials and their technological aspects will also be emphasized. References: 1. Dresselhaus, M. S., Adv. Mater. 2007, 19, 1043-1053. 2. Soni, A.; Yanyuan, Z.; Ligen, Y.; Aik, M. K. K.; Dresselhaus, M. S.; Xiong, Q., Nano Letters 2012, 12 (3), 1203. 3. Soni, A.; Yiqiang, S.; Ming, Y.; Yanyuan, Z.; Ligen, Y.; Xiao, H.; Zhili, D.; Aik, M. K. K.; Dresselhaus, M. S.; Xiong, Q., Nano Letters 2012, 12 (8) 4305
 Speaker: Dr. A K Sinha (Centre-Director, UGC DAE Consortium for Scientific Research, Kolkata) Title: Manipulating Ions for Science & Technology Date: November 25th, 2013 Time: 04:00 pm - 05:00 pm. Venue: FB 382 Abstract: We manipulate photons to form a beam of laser which finds numerous applications. In a somewhat similar way, we manipulate fast moving ions to use them in a very wide spectrum of scientific studies.Many technologies emerge out of these.I will try to cover some of the examples from my work involving such ion manipulations. Then i will make an attempt to dwell on such ion manipulations and their use in the Ion Beam Complex at IITK.
 Speaker: Dr. Bholanath Pahari (IISc Bangalore) Title: Probing Microscopic Information of Complex Materials by Nuclear Magnetic Resonance Techniques. Date: November 21th, 2013 Time: 11:00 am - 12:00 noon. Venue: FB 382 Abstract: Solid-state nuclear magnetic resonance (NMR) spectroscopy is a powerful physical method widely applied in modern fundamental and applied science. The two most important modes of solid state NMR for obtaining local physical and chemical information are wide-line static NMR and high-resolution magic angle spinning (MAS) NMR. Applications of both NMR modes and their advantages for the investigation of different categories of complex material will be discussed. Present seminar targets following three different topics. 51V NMR studies to understand the nature of ground state and low-lying excitations in the integer spin chain (also known as Haldane chain) compound SrNi2V2O8. 75As NMR for the investigation of electronic and lattice properties of recently discovered iron arsenide high-temperature superconductor CeFeAsO1−xFx (TC ∼ 40 K). Multinuclear MAS NMR studies to understand the structure - property relationships in oxide-ion conducting materials of P − doped La2Mo2O9 .
 Speaker: Dr. Shirish Chodankar (SLS, Paul Scherrer Institut, Switzerland) Title: Hydration forces and ion-ion correlation in confined fluids revealed by X-ray Reflectivity Date: November 18th, 2013 Time: 11:30 am - 12:30 pm. Venue: FB 382 Abstract: When a liquid is confined within a nanometer-sized gap, the combination of interfacial effects and size often confer to the system properties much different from those observed in bulk fluids [1]. In particular, understanding the structure of electrolytes confined between two aluminium-phyllosilicates walls could be enlightening in a number of fields, ranging from biology to nuclear waste management, as well as clarify some fundamental issues regarding alkali hydration energies and their influence on the surrounding hydrogen bond network. We have adapted a surface force apparatus (SFA) [2] to be used as confinement device for two sets of X-ray reflectivity (XRR) experiments conducted at the cSAXS (XSA12) beamline of the Swiss Light Source at PSI. In the first set of experiments, we determined by use of XRR the distance between the surfaces and the electron density profile of the naturally present water across the hydrophilic gap at nominal zero humidity [3]. In the second set, the natural layer of K+ ions present on cleaved mica surfaces was substituted with monovalent Rb+ or divalent Sr2+ ions. In the third set droplets of RbCl, CsCl and BaCl2 solutions at different concentrations were nano-confined. We have quantitatively determined the minimum gap distance between the mica surfaces at ~ 105 Pa applied pressure under the influence of different surface ions and electrolytes. In all cases we have observed layered electron density profiles within the gap, with the layering generally being stronger for more strongly correlated systems. A comparison between confined chloride solutions with different monovalent and divalent cations (Cs+ , Rb+ and Ba2+) reveals cation specific effects which can be related to concentration, ion size and hydration behavior. For example, we observe characteristic differences between the relative proportions of hydrated inner- and outer-sphere species and in the coverages of the inner membrane surfaces by directly adsorbed ions. Moreover, ordering in strongly correlated BaCl2 is interpreted as alternate cation-anion layering. Structure models for the measured density profiles will be presented and discussed. References: 1. Israelachvili, J.N., Intermolecular and surface forces: revised third edition. 2011: Academic press. 2. Perret, E., et al., Molecular liquid under nanometre confinement: density profiles underlying oscillatory forces. Journal of Physics: Condensed Matter, 2010. 22(23): p. 235102. 3. Chodankar, S., et al., Density profile of water in nanoslit. EPL (Europhysics Letters), 2012. 99(2): p. 26001.
 Speaker: Dr. Saurabh Mani Tripathi Photonics Research Centre, Department of Computer Science and Engineering, University of Quebec at Outaouais, Canada. Title: Long period grating and multimodal interference effect based fiber-optic sensors Date: October 21st, 2013 Time: 3 pm - 4 pm Venue: FB 382 Abstract: In this seminar I will present my resent research activities on the development of fiber-optic sensors based on (I) long-period gratings and (ii) single-multi-single (SMS) fiber optic structures. The first part of my talk will deal with the development of bio-sensors for rapid, reliable and quantitative detection of pathogenic E. coli bacteria in water. In the second part I will discuss the role of a critical wavelength in the performance of fiber optic devices based on modal interference. Application of modal-interference effects in bio-therapy will also be discussed.

### Quic Talk:

 Speaker: A. Kani (Dept. Of Physics, IITK) Title: Harnessing quantum interference in atomic systems Date: October 7th, 2013 Time: 4 pm - 5 pm Venue: FB 382 Abstract: Quantum interference between the excitation pathways modifies the optical response of the atomic system and leads to Coherent Population Trapping (CPT) and/or Electromagnetic Induced Transparency (EIT), or Electromagnetic Induced Absorption (EIA), or Amplification without Inversion (AWI), or Enhanced Refractive Index with vanishing absorption. We will present a simple four-level atomic system interacting with a bi-chromatic light field (double V-system) and discuss all these quantum interference effects and discuss the way to control over these effects.

### Seminar:

 Speaker: Dr. Sayantani Bhattacharyya (Ramakrishna Mission Vivekanand University) Title: Detecting biomass burning emission over South East Asia from space. Date: September 16th, 2013 Time: 11 am - 12 am Venue: FB 382 Abstract: Fluid dynamics is controlled by Navier Stokes equation. On the other hand Einstein equations control the dynamics of classical gravity. Both are complicated non linear partial differential equations with rich structure in the space of solutions. As a consequence of AdS/CFT conjecture we expect a duality between the solutions to these two sets of equations at least in certain regime. The goal of this talk would be to explore this duality between these two very different systems.
 Speaker: Dr. Sourish Basu (SRON Netherlands Institute for Space Research, Utrecht, Netherlands) Title: Detecting biomass burning emission over South East Asia from space. Date: August 12th, 2013 Time: 04:00 pm - 05:00 pm. Venue: FB 382 Abstract: Among the different components constituting anthropogenic CO2 emissions, biomass burning is the most uncertain. Current methods to quantify emissions from biomass burning -- such as forest fires and agricultural waste burning -- include satellite imaging to detect burnt areas and smoke plumes. However, these methods often underestimate large fire events since satellite are blind in the presence of smoke and aerosols that accompany large fires. I will describe a different -- and still developing -- method to quantify biomass burning emissions, which is to derive surface fluxes of CO and CO2 from observed gradients of those gases. Since most areas with widespread fires are devoid of surface monitoring stations, the observed gradients will be derived from satellite data. I will show how, using independent measurements of CO and CO2, we can detect fire events and quantify the amount of biomass burned.
 Speaker: Dr. Pintu Das (Institute of Physics, Goethe University – Frankfurt, Germany) Title: Magnetization dynamics in nano-/micro-structures using 2DEG-based micro-Hall magnetometry Date: August 8th, 2013 Time: 04:00 pm - 05:00 pm. Venue: FB 382 Abstract: With the fast development of data storage technologies, studying the magnetization as well as domain-wall dynamics in magnetic nano- as well as micro-structures have recently found immense attention of researchers active in the field of magnetism [1]. Investigations have been carried out for arrays or assembly of magnetic particles of nanometer scale dimensions. However, measurements of assembly of particles lead to an average signal and during this process many interesting and important information get lost resulting in an incomplete understanding of the internal dynamics of individual domains or domain walls. Therefore, investigations of individual (i.e., single) magnetic entities of nano-/micron-scale dimensions are important in order to understand the magnetization process in great details. Such data can also be directly used to test the existing theories [2].Motivated by these factors, we performed magnetic measurements of single ferromagnetic particles of micron and nano-scale dimensions using micro-Hall magnetometry method based on two-dimensional-electron-gas (2DEG) in the heterostructure of GaAs/AlGaAs. In this talk, I will discuss the results of measurements on a single CrO2 micro-crystal. With our high-sensitive measurement method, we were able to observe the transition from three-domain state to a two-domain state with a single domain-wall (separating the two domains), which was supported by micro-magnetic simulations [3]. Furthermore, we were able to track the motion of the domain wall through the sample and observed Barkhausen jumps due to the interaction with the pinning centres. Overall, the results demonstrate that micro-Hall magnetometry measurements can be used to obtain quantitative and detailed information of magnetization reversal process in individual particles of nano and micron scale dimensions. The results also allow us to estimate the density of pinning centres as a function of temperature. References: [1] S. Parkin et al, Science, 320, 190 (2008). [2] K. S. Novoselov et al, Nature 426, 812 (2003). [3] P. Das et al., Appl. Phys. Lett. 97, 042507 (2010); J. App. Phys. 112, 053921 (2012).

### QuiC Talk:

 Speaker: Dr. Anand K. Jha (Dept. Of Physics, IIT Kanpur) Title: Temporal Coherence in Two-Photon Interference - II Date: July 4th, 2013 Time: 11:00 am - 12:00 noon. Venue: FB 482
 Speaker: Dr. Anand K. Jha (Dept. Of Physics, IIT Kanpur) Title: Temporal Coherence in Two-Photon Interference Date: June 18th, 2013 Time: 11:00 am - 12:00 noon. Venue: FB 482 Abstract: In the earlier two talks, we had discussed two-photon interference and entanglement from a very broad perspective. The aim of this talk (and the next few) is to get into in-depth discussions about two-photon interference and related phenomena. In this talk we will be discussing the role of temporal coherence and indistinguishability in two-photon interference. We will keep our discussions of temporal coherence centered around parametric down-conversion, a non-linear optical phenomenon that produces entangled two-photon field.
 Speaker: Dr. Kedar B. Khare (Dept. Of Physics, IIT Delhi) Title: How many measurements are needed to generate an N-pixel image? Date: June 10th, 2013 Time: 11:00 am - 12:00 noon. Venue: FB 382 Abstract: In Scientific and Technological research ranging from sub-nano to astronomical length scales, imaging systems are playing a key role as tools that allow us to visualize natural phenomena or objects of interest,thereby, directly influencing new discoveries. With ever increasing demands on imaging performance (e.g. resolution, speed, sensitivity to noise, etc.), it is becoming clear that imaging systems of tomorrow need to acquire, process and utilize imaging data in an efficient non-redundant manner. In this seminar I will discuss some current ideas on imagerecovery from "incomplete" or sub-Nyquist sampled data with examples from my own research work in diagnostic healthcare and optical imaging. It will be shown that a hybrid approach - combining imaging hardware and new image recovery algorithm ideas - allows us to overcome conventionally perceived limits on imaging systems.

### High Energy Physics Seminar:

 Speaker: Dr. Anurag Sahay ( Inst. of Physics, Bhubaneswar) Title: Tunnelling in Anti de Sitter Space and in its Boundary Matrix Dual Date: 07.06.2013 ( Friday) Time: 4:00 PM Venue: FB 382 Abstract: For charged black hole, within the grand canonical ensemble, the decay rate from thermal AdS to the black hole at a fixed high temperature increases with the chemical potential. We check that this feature is well captured by a phenomenological matrix model expected to describe its strongly coupled dual. This comparison is made by explicitly constructing the kink and bounce solutions around the de-confinement transition and evaluating the matrix model effective potential on the solutions.

### QuIC Talk (Quantum Information and Coherence)

 Speaker: Dr. Anand Kumar Jha (Dept. Of Physics, IIT Kanpur) Title: Two-Phonton Interference and Entanglement - II Date: May 7th, 2013 (Friday) Time: 4:15-5:15 pm Venue: FB-382

### QuIC

 Speaker: Dr. Anand Kumar Jha (Dept. Of Physics, IIT Kanpur) Title: Two-Phonton Interference and Entanglement - I Date: May 3rd, 2013 (Friday) Time: 3:45-5:00 pm Venue: FB-382

### Seminar:

 Speaker: Prof. S. Dutta Gupta (University of Hyderabad, Hyderabad) Title: Bending light the wrong way! Date: 17 April 2013 Time: 3.00 PM Venue: FB 382

### HEP:

 Speaker: Ravi Manohar (IITK) Title: A lightfront non-perturbative study of generalized parton distributions Date: March 12, Tuesday Time: 4 pm Venue: FB-382 Abstract: We give a study of interface between the nonperturbative lightfront amplitude calculation for an electron in a trap and an experimentally-accessible distribution functions using such light front amplitudes. It will be helpful to investigate these distribution functions at weak (QED) coupling as well as at an artificially large coupling. Additionally it will be interesting to map out the effects of a confining potential (external harmonic oscillator) trap on these distribution functions. Epoch to this project, we investigate the generalized parton distributions H(x,\zeta;,t) in the forward limit for a dressed-electron using the nonperturbative lightfront amplitude calculated in the harmonic oscillator basis.
 Speaker: Mridupawan Deka (JINR, Dubna, Russia). Title: Quark and Gluon Angular Momenta Contributions to Nucleon Spin Date: 26 February, Tuesday Time: 4 pm Venue: FB-382 Abstract: The nucleon spin structure has been a longstanding issue in hadronic physics, both experimentally and theoretically. From the polarized Deep Inelastic Scattering experiments and Lattice QCD calculations, it has been found that the contribution coming from the quark spin is rather small (~25%). Now, it is widely accepted that the rest of the nucleon spin should come from the gluon spin and the orbital angular momenta of quarks and gluons. In this talk, I will present a complete Lattice QCD calculation of the quark and glue angular momenta inside a proton. The calculation is carried out on a 16^3×24 quenched lattice using the standard Wilson action.

### Seminar:

 Speaker: Dr. R. Chelakkot, School of Engineering and Applied Sciences (SEAS), Harvard University, USA Title: Semiflexible polymers: Instabilities under confinement, constraint and activity. Date: 18 February (Monday) Time: 4:00 PM Venue: FB 382

### HEP:

 Speaker: Bindusar Sahoo (Nikhef, Amsterdam) Title: Topologically massive higher-spin gravity Date: February 13, wednesday Time: 4 pm Venue: FB-382 Abstract: In the last couple of decades a theory has been developed by Vasiliev to consider interacting theories of fields with spin greater than 2 which is known as higher-spin gravity. This theory has received a lot of attention recently in the context of AdS-CFT correspondence. The theory in various dimensions is conjectured to be dual to well known conformal field theories in the boundary. In the light of this recent development, we will discuss the higher-spin analogue of topologically massive gravity in three dimensions, which we call topologically massive higher-spin gravity. We will start with a brief introduction and motivation to consider higher-spin theories. This will be followed by a brief introduction and overview of current results in higher-spin theories and topologically massive gravity. This will be followed by our work on topologically massive higher-spin gravity. We will discuss various semi classical as well as quantum results of the theory considered by us.
 Speaker: Arnab Kundu (Univ of Texas at Austin) Title: Dynamics of Fundamental Flavours in Holographic Duals of Large N Gauge Theories. Date: Feb 4, 2013 Monday Time: 2:30 pm Venue: FB-382 Abstract: Using the gauge-gravity duality, more specifically the AdS/CFT correspondence, we will discuss strongly coupled dynamics of fundamental flavours in large N gauge theories. We will primarily focus on the physics of chiral symmetry breaking by introducing flavour degrees of freedom in the so called Klebanov-Witten model. We will discuss the physics of the flavour sector in and beyond the probe limit. We will conclude with some general remarks.

### Seminar:

 Speaker: Dr. Umakanta Tripathy (Visiting Scientist, TIFR, Mumbai) Title: Detecting malaria and imaging extra cellular matrix in tissues by multi-modal nonlinear laser scanning microscopy (NLSM) Date: 5th February, 2013 Time: 12:00 noon Venue: FB 382 Abstract: Multi-modal nonlinear laser scanning microscopy (NLSM), also known as multiphoton microscopy or higher harmonic generation microscopy is a powerful research tool that combines the advanced optical techniques of laser scanning microscopy with long wavelength multi- photon fluorescence excitation to capture high resolution and threedimensional (3D) images of specimens. Some of the core advantages that include label free imaging, depth imaging & minimizing photo-bleaching allows investigations on thick, living and fixed cells/tissues that would not otherwise be possible with conventional imaging techniques. Two-photon fluorescence (TPF), second harmonic generation (SHG), & third harmonic generation (THG) techniques are used as imaging tools. In the present talk, we will focus the use of multi-modal NLSM as an imaging device for the early detection and quantification of the malaria pigment (hemozoin) by THG technique. The obtained results will guide the optimal design of malaria detection technologies that exploit the THG response of hemozoin. In addition, multi-modal NLSM imaging of extra cellular matrix in tissues (collagen and elastin) to investigate the structural remodeling of the human ascending aorta with dilation, and documenting the geometrical properties of vocal folds (human & porcine) by SHG and TPF technique will also be presented. The results acquired would provide valuable information for better understanding the tissue biomechanics that may assist clinicians for rapid and reliable disease diagnosis.

### HEP:

 Speaker: Prof. Dharam Vir Ahluwalia (Universidade Estadual de Campinas, Brazil and TIFR) Title: Elko Spinors and dark matter Date: 17 January, Thursday Time: 11 AM - 1 PM and 4 PM - 6 PM (with refreshment breaks) Venue: 382 FB

### Seminar:

 Speaker: Dr. Prasanna Kulkarni, ( Departamento de Fisica de la MateriaCondensada,Universidad Autonoma de Madrid, Madrid,Spain ) Title: Elko Spinors and dark matter Date: 17 January, Thursday Time: 11 AM - 1 PM and 4 PM - 6 PM (with refreshment breaks) Venue: 382 FB
 Speaker: Title: Date: Time: Venue: Purnendu Chakraborty Gluon condensate and nonperturbative QCD propagators above deconfinement temperature 02 Jan 2013 (Wednesday) 4:00 PM (FB382) Speaker: Title: Date: Time: Venue: Udai Raj Singh Inhomogeneous superconducting gap and symmetry breaking in FeSe0.4Te0.6 studied by spectroscopic imaging STM 27 Dec 2012 (Thursday) 11:00 AM (FB382) Speaker: Title: Date: Time: Venue: Dr. T. Arun Kumar Study of perfluoropolymer as an alignment layer for nematic liquid crystals 27 Dec 2012 (Thursday) 4:00 PM FB382 Speaker: Title: Date: Time: Venue: Prof. Dharam Vir Ahluwalia Elko Dark Matter 24 Dec 2012 (Monday) 4:00 PM FB382 Speaker: Title: Date: Time: Venue: Dr. Amar Nath Gupta Transition path time, diffusion constant and folding rate of protein determined from reconstructed free-energy landscape analysis 12 Dec 2012 (Wednesday) 4:00 PM (FB382) Speaker: Title: Date: Time: Venue: Dr. Shiva Kumar Malapaka, Leeds University, UK A study of magnetic helicity in forced and decaying 3D-MHD turbulence 4 pm FB-382 Speaker: Title: Date: Time: Venue: Dr. Anindya Das Superconductor-semiconductor junctions: Cooper pairs splitting and Majorana quasiparticles 22 Nov 2012 (Thursday) 4:00 PM (FB382) Speaker: Title: Date: Time: Venue: Dr. Naveen Kumar Relativistic beam-plasma interaction and its applications for particle acceleration and fast ignition fusion in plasmaa 20 Nov 2012 (Tuesday) 11:00 am FB 382 Speaker: Title: Date: Time: Venue: T. K. Saxena Automation in research and industry 6th Nov 2012 (Tuesday) 4:00 pm FB 382

 Speaker: Title: Date: Time: Venue: Dr. Dinesh Kabra, Cavendish Laboratory, University of Cambridge, UK. Molecular Semiconductors: Charge Transport, Structural and Spectroscopic based Investigations 12 Jan 2012 (Thursday) 4:00 pm FB 382 Speaker: Title: Date: Time: Venue: Swarn Lata Singh (BHU)) Free-energy functional for symmetry broken ﬁrst order phase transitions 11 January 2012 4:00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Amit Agarwal (Scoula Normale, Pisa, Italy) Collective excitations in strongly spin-orbit coupled two dimensional electron gases 2 January 2012 4:00 pm FB 382 Speaker: Title: Date: Time: Venue: Pomita Ghoshal (HRI) Determining the Neutrino Mass Hierarchy via Future Atmospheric Neutrino Detectors December 30 (Friday) 4:00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Chary Rangayajulu, University of Saskatchewan, Canada Laser Compton Scatter MeV Photons at Light Sources for Nuclear andAllied Sciences 19th December, 2011 (Monday) 4:00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Amit Sharma, Seagate Technology, USA An Integrated Heat Assisted Magnetic Recording System 2nd November, 2011 (Wednesday) 2.30 pm FB 382 Speaker: Title: Date: Time: Venue: Gopal, IITK Collider Implication of Weyl Meson. 18 October, Tuesday 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: M. Ranaul Islam (Strathclyde University, Glasgow, UK) Laser Wakefield Accelerator: Towards Gamma-Rays 17 October, 2011 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Anand Kumar Jha, Intel Corporation, USA Two-Photon Fields: Coherence, Interference and Entanglement 27 September, 2011 (Tuesday) 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Kaushik Bhattacharya (IITK) Lee-Wick thermodynamics and its effect in the early universe 20 Sept, 2011, Tuesday 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Soumen Mandal, Institut Neel, CNRS and Universite Joseph Fourier,BP 166, 38042 Grenoble cedex 09, France Diamond as a material for nano-mechanical and quantum devices 7 Sept, Wednesday 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Archana Tiwari, School of Chemical and Physical Sciences, Sikkim University Fluorescent balls with an effective spin 06 Sept 2011 (Tuesday) 2.30 pm FB 382 Speaker: Title: Date: Time: Venue: Prabhakar Tiwari (IITK) Large Scale Alignments in Quasar Polarizations due to pseudoscalar-photon mixing in intergalactic magnetic fields Sept 06, Tuesday 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Swati Bhattacharya (Univ. of Illinois, Urbana, USA) Designing nanopore sensors: laying the foundations of personalgenomics 5 September, 2011 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dipankar Chakrabarti (IIT Kanpur) A study of generalized parton distributions in position space. 23 Aug, Tuesday 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Udit Raha (Univ. Basel) Electromagnetic Pion and Kaon Form Factors in Light-cone QCD 17 Aug, Wednessday 5.00 pm FB 382 Speaker: Title: Date: Time: Venue: Kumar Rao (Helsinki Univ) Top Polarization as a probe of New Physics 02 Aug(Tuesday), 2011 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Amitesh Paul, Technische Universität München, Germany Polarized neutron scattering in nano-layered systems 01 August 2011 (Monday) 4.00 pm to 5.00 pm FB 382

 Speaker: Title: Date: Time: Venue: Prof. Deepak Kumar (JNU) Anomalous heat transport in quantum chains 27 July 2011 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dinesh Kumar Shukla, Deutsches Elektronen-Synchrotron (DESY), Hamburg, Germany Resonant and non-resonant magnetic x-ray scattering on multiferroic HoFe3(BO3)4 29 July 2011 (Friday) 3.00 pm to 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Subhadeep De, Joint Quantum Institute (JQI), National Institute for Standards and Technology (NIST) and University of Maryland (UMD), Maryland, USA. Facility to produce ultra-cold degenerate Bose and Fermi gasses 21 July 2011 (Thursday) 4:00pm FB-382. Speaker: Title: Date: Time: Venue: Dr. Bhaskaran Muralidharan, MIT,USA Microscopic modeling of non equilibrium electronic and thermoelectric transport phenomena at nanoscale 15 March, 2011 (Tesday) 3:00 PM FB 382 Speaker: Title: Date: Time: Venue: Proffesor B.S. Acharya, TIFR, Mumbai The universe viewed in Gamma rays 4 March, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Proffesor Anjan Kumar Gupta, IIT Kanpur STM trip induced carrier doping in graphene with puddles 4 March, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Vinod Chandra Joshi, TIFR, Mumbai A quasi particle description for (2+1)-flavor equation of state 15 February, 2011 (Tuesday) 4.00 PM FB 382 Speaker: Title: Date: Time: Venue: Proffesor Sukanta Panda, IISER, Bhopal Detecting high to ultra high energy cosmic ray 11 February, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Narendra Sahu, Uni. Libre de Bruxelles, Belgium Direct and indirect search of dark matter interacting via Higgs Portal 8 February, 2011 (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Professor sanjoy Swain, NEISER, Bhubaneswar Introducing to Large Hadron Collider (LHC) 28 January, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. T.R. Govindarajan, Institue of Mathematical Science Gravity and Geometry-Hundreds year after Einstein 17 January, 2011 (Monday) 11:30 AM FB 382 Speaker: Title: Date: Time: Venue: Dr. Jayanti Prasad, IUCAA, Pune Cosmological N-body simulatio: Techniques, scope limitation 18 January, 2011 (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Professor Steven Tomsovic, Washington State University What is measured in the scanning gate microscopy of a quantum point contact? 13 January, 2011 (Thursday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Bhaskaran Muralidharan, MIT,USA Microscopic modeling of non equilibrium electronic and thermoelectric transport phenomena at nanoscale 15 March, 2011 (Tesday) 3:00 PM FB 382 Speaker: Title: Date: Time: Venue: Proffesor B.S. Acharya, TIFR, Mumbai The universe viewed in Gamma rays 4 March, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Proffesor Anjan Kumar Gupta, IIT Kanpur STM trip induced carrier doping in graphene with puddles 4 March, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Vinod Chandra Joshi, TIFR, Mumbai A quasi particle description for (2+1)-flavor equation of state 15 February, 2011 (Tuesday) 4.00 PM FB 382 Speaker: Title: Date: Time: Venue: Proffesor Sukanta Panda, IISER, Bhopal Detecting high to ultra high energy cosmic ray 11 February, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Narendra Sahu, Uni. Libre de Bruxelles, Belgium Direct and indirect search of dark matter interacting via Higgs Portal 8 February, 2011 (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Professor sanjoy Swain, NEISER, Bhubaneswar Introducing to Large Hadron Collider (LHC) 28 January, 2011 (Friday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. T.R. Govindarajan, Institue of Mathematical Science Gravity and Geometry-Hundreds year after Einstein 17 January, 2011 (Monday) 11:30 AM FB 382 Speaker: Title: Date: Time: Venue: Dr. Jayanti Prasad, IUCAA, Pune Cosmological N-body simulatio: Techniques, scope limitation 18 January, 2011 (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Professor Steven Tomsovic, Washington State University What is measured in the scanning gate microscopy of a quantum point contact? 13 January, 2011 (Thursday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. A. Nagar (Max-Planck Institute, Golm, Germany) Effect of mutators on evolution 11 November 2010 (cancelled) 4.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Deepshikha Jaiswal-Nagar Goethe University, Frankfurt Magnetocaloric effect and magnetic cooling near a field-induced Quantum-critical point 12 November 2010 (Friday)(cancelled) 4.00 pm to 5.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. N.S. Vidhyadhiraja (JNCASR, Bangalore) Dynamics and transport in paramagnetic heavy fermion systems. 10 November 2010 (Wednesday) 4.00 pm to 5.00 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. Rajib Sarkar, Max-Planck Institute CPfS, Dresden, Germany Interplay between Ce-4f and Fe-3d magnetism in CeFe(As/P)O as seen by NMR. 1st November (Monday) Time: 3:0 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Debaprasad Maity , National Taiwan University Some issues on Randall-Sundrum Brane World models 26 October, 2010, Tuesday 5 pm FB 382 Speaker: Title: Date: Time: Venue: Sarmistha Banik Effect of Shear Viscosity on the Nucleation of Antikaon Condensed Matter in Neutron Stars 20 October, Wednesday 4:00pm FB-382. Speaker: Title: Date: Time: Venue: Anand Sengupta(Delhi Univ) Search for gravitational waves from binary blackholes in LIGO's S5 data 29th sept, Wednessday 4 pm FB 382 Speaker: Title: Date: Time: Venue: Pankaj Jain, IIT Kanpur Local Scale Invariance may solve the cosmological constant problem September 14, Tuesday 4 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. M. K. Niranjan (IIT, Hyderabad) Novel Interface Magnetoelectric Effects in Oxide Heterostructures: Design and prediction from first-principles 23 Aug4 pm FB 382 Speaker: Title: Date: Time: Venue: Pankaj Jain Local Scale Invariance may solve the cosmological constant problem September 7, Tuesday (postponed) 4 pm FB 382 Speaker: Title: Date: Time: Venue: Naveen Surendran, ICTP, Trieste, Italy Topological order in three dimensions 14 May 2010 4 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. P. Ghosh (ICTP, Trieste) Atomistic modeling of materials 13 May 2010 4 pm FB 382 Speaker: Title: Date: Time: Venue: Dr. K. S. Nagapriya, Israel Torsional Electromechanics of Carbon and Inorganic Nanotubes Tue, 20 April 2010 5.15 pm FB 382 Speaker: Title: Date: Time: Venue: Abhijit Samanta (HRI) Atmospheric neutrinos in future neutrino oscillation experiments 20 th April (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Naveen Kumar Singh Effective Field theory of Gravity March 23, 2010 (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Prof. J Maharana Axion Dilaton Q Cosmology. March 18 ,2010 (Thursday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Arnab Chatterjee, The Abdus Salam International Centre for Theoretical Physics, Trieste, Italy Effective Field theory of Gravity 15th March,2010 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Prof. P. Majumdar (SINP) Effective Field theory of Gravity March 11 (Thursday) 4:30 PM FB 382 Speaker: Title: Date: Time: Venue: Naveen Kumar Singh (Postponed) Effective Field theory of Gravity March 09, 2010 (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. P S Mohanty, University of Fribourg, Switzerland Responsive Colloids as a Model System in Condensed Matter Physics 22 February, Monday 4-5 PM FB 382 Speaker: Title: Date: Time: Venue: Kaushik Bhattacharya An unusual extension of statistical mechanics in the unusual quantum field theory. 23 February, Tuesday 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Prof. Avinash Khare, IOP, Bhubaneshwar Supersymmetric Quantum Mechanics 17 February, Wednesday and 18 February, Thursday 4-6 PM FB 382 Speaker: Title: Date: Time: Venue: Suresh Govindarajan (IIT Chennai) New Lie algebras from dyonic black holes 21 January 2010 (Thursday) 4:00pm FB 382 Speaker: Title: Date: Time: Venue: Dr. A.K. Shukla, Institut Jean Lamour, UMR 7198 CNRS, 54042 Nancy, France Metal adlayers grown on quasicrystalline surfaces 15th January 2010 (Friday) 12:00 Noon FB 382 Speaker: Title: Date: Time: Venue: Akhlesh Lakhtakia Copycat science and technology 04 Jan 2010 (Monday) 4:00 p.m. to 5:00 p.m. FB 382 Speaker: Title: Date: Time: Venue: Vinod Chandra Joshi (TIFR) Properties of hot and dense matter produced in heavy ion collisions January 5, 2010 4:00pm (tea @ 3:45pm) FB 382 Speaker: Title: Date: Time: Venue: Prof. Govind Swarup, NCRA, TIFR, Pune New Questions at the Frontiers of Radio Astronomy: Giant Metrewave Radio Telescope near Pune, Recent Results and Challenging Projects 10 December, 2009, Thursday 4 PM FB 382 Speaker: Title: Date: Time: Venue: Aakash Basu, Department of Applied Physics, Stanford University Mechanochemistry of DNA Gyrase - a processive molecular motor 24 November (Tuesday) 2.30 PM FB 382 Speaker: Title: Date: Time: Venue: Rajeev Bhalerao (TIFR, Mumbai) Transport properties of the fluid produced at RHIC 24 November, Tuesday 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Golam M Hossain (University of New Brunswick, Canada) Driving cosmic inflation on a bumpy road November 3, Tuesday 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. Aveek Bid, Weizmann Institute of Science, Israel Euclidean formulation in black hole thermodynamics October 28, 2009 (Wednesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Anurag Sahay Euclidean formulation in black hole thermodynamics 27/10/09, Tuesday (postponed) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: A. Pavan Kumar CMB polarization power spectrum and its Estimation October 20, Tuesday 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Prof. R Ramachandran (IISER, Pune) Are there massive long lived states in string theory? October 16, Friday 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr. G.N. Shanmugha Sundaram SKA Design, Evalution, Optimization Issuses September 16 (Wednesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Pankaj Jain Conformal Standard Model September 2 (Wednesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr T Sarkar Recent Developements on helium core white dwarf stars 25 August (Tuesday) 4:00 PM FB 382 Speaker: Title: Date: Time: Venue: Dr Arunansu Sil Inflation and Supersymmetry Breaking 18 August (Tuesday) 4:00 PM FB 382
 Speaker: Institution: Title: Date: Arindam Kundagrami University of Massachusetts, Amherst, USA Physics of charged polymers: effective charge, size, phase transitions, and other properties as soft materials March 2, 2009 Speaker: Institution: Title: Date: Archana Pai Max Planck Institute fur Gravitationsphysik Fishing gravitational wave chirps with a multi-detector network December 29, 2008

### Horizon Lecture

 Speaker: Institution: Title: Date: Deepak Mathur UM-DAE CBS and TIFR, Mumbai Adventures on the interface of physics and biology November 8, 2008

### Fourth Prof. Jagadishwar Mahanty Lecture

 Speaker: Institution: Title: Date: Deepak Mathur UM-DAE CBS and TIFR, Mumbai Interaction of intense light with matter.... and of matter with intense light November 7, 2008 Speaker: Institution: Title: Date: Arul Lakshminarayan IIT Madras Some Instances of Extreme Value Statistics in Physics October 23, 2008 Speaker: Institution: Title: Date: Dipankar Chakraborti. University of Wales Swansea, UK Diffraction pattern in deeply virtual Compton scattering August 8, 2008 Speaker: Institution: Title: Date: Nilotpal Ghosh University of Leipzig, Germany Andreev Reflection and Physical Property Measurements August 4, 2008

 Speaker Affiliation Title Date Hemant Shukla University of California, Berkeley Simulating the Supernova/Acceleration Probe (SNAP) Mission for Exploring Dark Energy March 28, 2008 Speaker Affiliation Title Date Ajit M. Srivastava Institute of Physics, Bhubenswar Super-horizon fluctuations and acoustic oscillations in relativistic heavy-ion collisions March 13, 2008 Speaker Affiliation Title Date Douglas W. McKay IIT Kanpur and Univ. of Kansas. Examining the Cosmic Ray Knee February 14, 2008 Speaker Affiliation Title Date P.K. Panigrahi Physical Research Laboratory, Ahmedabad Solitons in Bose Einstein Condensates (BEC) in a Trap and Optical Lattice September 5, 2007 Speaker Affiliation Title Date Colin Benjamin Centre de Physique, Marseille, France Controllable pi junction in a Josephson quantum-dot device with molecular spin August 10, 2007 Speaker Affiliation Title Date Udit Raha University of Basel, USA Hadronic Atoms In Effective Field Theory August 3, 2007 Speaker Affiliation Title Date Vishal Saxena University of Southern California, USA A Non-invasive Multimodal Technique to Monitor Brain Tumour Vascularization April 26, 2007 Speaker Affiliation Title Date Vishal Saxena University of Southern California, USA Hot Electron Luminiscence in GaAs : Electric Field Effects April 25, 2007 Speaker Affiliation Title Date Ambar Jain MIT, USA Penguin Loops for Nonleptonic B decays in the Standard Model April 23, 2007 Speaker Affiliation Title Date Pankaj Jain IIT, Kanpur, India Cosmological Symmetry Breaking, Pseudo-scale invariance, Dark Energy and the Standard Model April 11, 2007 Speaker Affiliation Title Date Indrajit Mitra IIT, Kanpur, India Criterion for dynamical chiral symmetry breaking April 03, 2007 Speaker Affiliation Title Date Shiraz Minwalla TIFR, Mumbai, India Black holes in Yang-Mills Theories March 29, 2007 Speaker Affiliation Title Date Amihay Hanany MIT, USA Tiling dimers and quiver gauge theories March 22, 2007 Speaker Affiliation Title Date A. Taraphder IIT, Kharagpur Magnetic and orbital order in doped magnetoresistive systems March 20, 2007 Speaker Affiliation Title Date Narendra Sahu PRL, Ahmedabad A predictable unified model for dark matter, dark energy, neutrino masses and leptogenesis at the TeV scale March 12, 2007 Speaker Affiliation Title Date R. Rajesh IMSc, Chennai Statistics of Driven Dissipative Systems March 01, 2007 Speaker Affiliation Title Date R. Ramachandran IISER, Pune Decay of Massive String States February 28, 2007 Speaker Affiliation Title Date Balaji Birajdar Institute of Applied Physics, University of Tuebingen, Tuebinge, Germany Transmission Electron Microscopy of Superconducting MgB2 Tapes February 08, 2007 Speaker Affiliation Title Date Justin Raj David HRI,Allahabad From Spacetime to Worldsheet: Four Point Correlators February 01, 2007 Speaker Affiliation Title Date Amit Ghoshal UCLA,USA Diamagnetism of Nodal Fermions: Graphene and Others January 18, 2007 Speaker Affiliation Title Date Prasant Panigrahi PRL, Ahmedabad Study of Fluctuations through Wavelet Transform December 29, 2006 Speaker Affiliation Title Date T.K. Ghosh JEPS, Okayama, Japan December 27, 2006 Speaker Affiliation Title Date Umananda Dev Goswami Guwahati University Charmed Hadron Production in pp Interaction December 6, 2006 Speaker Affiliation Title Date Gopika Sood Punjab University Fluctuations with WA98 and STAR November 24, 2006 Speaker Affiliation Title Date Bhag Chauhan CFTP-Instituto Superior Technico, Lisbon Solar Neutrinos: Oscillations and Magnetic Moment November 17, 2006 Speaker Affiliation Title Date Prakash Mathews SINP, Kolkata QCD Prerequisites for Extra Dimensional Searches November 16, 2006 Speaker Affiliation Title Date Rajarshi Ray SINP, Kolkata QCD Thermodynamics: Lattice and PNJL Model November 13, 2006 Speaker Affiliation Title Date Dimitry Batani Universita di Milano Bicocca, Italy Transport of Intense Laser-produced Electron Beams in Matter October 30, 2006 Speaker Affiliation Title Date Swarnendu Sarkar IOP, Bhubaneshwar Phases of Asymptotically AdS Black Holes and Gauge Theory October 26, 2006 Speaker Affiliation Title Date A.K. Grover TIFR, Mumbai October 12, 2006 Speaker Affiliation Title Date K. Narayanan TIFR,Mumbai India Time Dependent Phenomena in String Theory October 9, 2006 Speaker Affiliation Title Date Sumathi Rao HRI, Allahabad Correlated Electron Transport Through Junctions of Quantum Wires September 19, 2006 Speaker Affiliation Title Date Manoj Gopalakrishnan HRI, Allahabad Stochastic Theory of Ligand Binding to Cell Membrane Surfaces August 18, 2006 Speaker Affiliation Title Date Subrata Bal Dublin Institute for Advanced Studies Dynamical Generation of Gauge Group in Matrix Model April 18, 2006 Speaker Affiliation Title Date E. Harikumar University of Sau Paulo, Brazil Dirac Operator on the q-deformed Fuzzy Sphere and its Spectrum April 17, 2006 Speaker Affiliation Title Date S. Ramakrishnan TIFR, Mumbai Multiple Phase Transitions inï¿½ RE5T4M10 (T=Rh, Ir andï¿½ M=Si, Ge, Sn) Compunds April 14, 2006 Speaker Affiliation Title Date Dieter Suter University of Dortmund Quantum Computing: Towards Scalability March 13, 2006 Speaker Affiliation Title Date Arun Bansil Northeastern University, Boston Modelling Electronic Structure and Spectroscopy of Complex Materials: ARPES, RIXS and STM March 06, 2006 Speaker Affiliation Title Date Shailendra Kumar Center for Advanced Technology, Indore Role of Plasma Waves and Thermal Waves in Study of Semiconductors March 01, 2006 Speaker Affiliation Title Date Tapobrata Sarkar Indian Institute of Technology, Kanpur Closed String Tachyons: Recent Developments February 23, 2006 Speaker Affiliation Title Date Som Bandyopadhyay University of Calgary Monogamy of Quantum Entanglement February 20, 2006 Speaker Affiliation Title Date Pankaj Jain Indian Institute of Technology, Kanpur Interferometric Parallax: A Method for Measurement of Astronomical Distances January 20, 2006 Speaker Affiliation Title Date Brian Dolan National University of Ireland, Maynooth Quantum Black holes: The Event Horizon as a Fuzzy Sphere January 13, 2006 Speaker Affiliation Title Date Chiranjib Mitra University College of London Electron Doped Manganites and their Spin Density of States from Tunneling Magnetoresistance and Spectroscopic Studies January 03, 2006 Speaker Affiliation Title Date Rajendra Singh Max-Planck Institute of Microstructure Physics, Weinberg (Germany) Strained Silicon On Insulator via Wafer Bonding and Layer Transfer Approach for Nano CMOS Applications November 22, 2005 Speaker Affiliation Title Date Chandan Dasgupta Indian Institute of Science, Bangalore Density Functional Theory of Hard Sphere Glasses November 18, 2005 Speaker Affiliation Title Date Arijit Bhattacharya University of Padova, Italy Dynamics of Pattern Formation in Reaction Diffusion Systems November 17, 2005 Speaker Affiliation Title Date Ninad Shinde Nagoya University, Japan Solid-State Physics Using Ion Beams: Spectroscopy and Irradiation Effects November 8, 2005 Speaker Affiliation Title Date Jyotipratim Ray Choudhury University of Burhawan, West Bengal A Semiclassical Approach to Kramerï¿½s Problem October 31, 2005 Speaker Affiliation Title Date Dipankar Chakrabarti University of Florida Helicity Non-Conserving Glu-Glue Scattering Amplitudes on the Light-Cone Worldsheet October 25, 2005 Speaker Affiliation Title Date Rajesh Narayanan University of Karlsruhe, Germany Griffiths Phase in Unconventional Quantum Hall Effect October 25, 2005