NMR LabFemto-Laser Lab Ultra-Low Temperature Lab BEC and Photons Lab Cosmology String Theory General Relativity Correlated & Disordered Electron Systems Nonlinear Dynamics & Complex Systems Quantum Computing Novel Materials Lab Statistical Physics Soft Matter Physics Biophysics Condensed Matter Physics Laser Physics Quantum Thermodynamics Physical Sciences IISER Mohali The Department of Physical Sciences has witnessed exciting growth in a short period of six years. This brochure represents, in a nutshell, this young and vibrant department. Our mission is to contribute to the advancement of the understanding of our physical world through basic and applied research, and engage students in the excitement in the world of physics. Our Department provides a challenging, yet supportive environment, in which to pursue research and teaching goals, and we have strived to create an atmosphere of collaboration and collegiality. Research in this Department covers incredible range, encompassing phenomena spanning length scales from nanometers to megaparsecs, and time scales from attoseconds to billions of years! There is great variety in the Department, and we house high performance computing facilities and many state-of-the-art research laboratories. The Department has been pro-active in running a successful teaching program, and my colleagues are seeking bright and energetic students to further strengthen and sustain the activities of the research groups, through the Integrated PhD, PhD and post-doctoral programs. Members of this Department are part of national bodies, such Programme Advisory Committees of DST and the National Board of Higher Mathematics, and they have received significant external funding and awards from several sponsored projects from DST, DBT and CSIR. Hope you enjoy this virtual walk through our Department! Sudeshna Sinha 27 September 2013 Quantum Information Dr. Arvind Professor Arvind is a theoretical physicist whose research interests span the areas of quantum information processing, quantum optics, foundations of quantum mechanics and research in physics education. Research Interests Quantum Computing: Quantum computers when functional, are expected to qualitatively outperform their classical counterparts. Characterising quantum entanglement and tracing its exact role in quantum algorithms remains a challenging open problem. I have worked on issues related to quantum entanglement in the context of the Deutsch-Jozsa algorithm and Parity Determining algorithm, quantum dissipation and its control, optical schemes for quantum computers and NMR implementations of quantum information processors. My current research interests in quantum information include characterisation of bound state entanglement, role of entanglement in quantum computation, quantum crytography and physical implementations of quantum computers. normal modes and symmetry breaking in a 2D pendulum using a single oscillator. Phys. 24. Phd students and postdocs working in my group: Ritabrata Sengupta. • Ritabrata Sengupta and Arvind. 032328. (2007). • Geetu Narang and Arvind. J. A 75. different approaches to the quantum measurement problem and in particular understanding weak measurements. (2012). Experiments developed so far include random sampling of an AC source with a DC meter. • Arvind. Am. Rev. . Gurpreet Kaur and Geetu Narang. Harpreet Singh (jointly with Dr Dorai). A. Rev. Shruti Dogra (jointly with Dr Dorai). geometric phases in quantum mechanics. Rev. 84. 221 (2007). and a quantitative study of ion diffusion. Opt. (2011). and application of group theoretic methods in quantum optics. Dr Roman Sverdlov Selected Recent Publications • Ritabrata Sengupta and Arvind. Phys. Phys. 032305. sub-Poissonian photon statistics and antibunching. 87. Physics Education: I am working on building new experiments for physics teaching which are designed around a certain conceptual theme. B. Quantum Optics: My research in quantum optics includes signatures of nonclassical behaviour for the radiation field such as squeezing.Foundations of Quantum Mechanics: I have also been working on connection of Bell's inequalities with non-classicality of states of the radiation field. A. formulation of Bell's inequalities for multi-photon sources. Debmalya Das. Soc. a demonstration of Coriolis force. 012318. He worked as a post-doctoral research associate at the Institute of Astronomy. as a faculty member in 1999. This process amplifies tiny fluctuations in density and leads to formation of highly over dense regions called halos. Suites of simulations have also been used to point out deviations from certain strong assumptions . J. My contribution in this field has been in development of highly optimized methods for doing cosmological N-Body simulations. Allahabad. Pune in 1996. J. S Bagla completed his PhD from IUCAA. Research Interests I work on questions related formation of galaxies and large scale structure within the framework of the standard cosmological model. University of Cambridge for two years. We have used these simulations to study the process of gravitational clustering and demonstrate that this process erases differences between different types of initial fluctuations. S. It is believed that the large scale structure forms due to gravitational collapse around over dense regions. Bagla Prof. and then at the Harvard-Smithsonian Centre for Astrophysics for slightly over a year before joining the Harish-Chandra Research Institute. The process of gravitational collapse in an expanding universe is fairly complex and we are required to simulate this on super computers in order to follow relevant details.Cosmology Prof. Galaxies are believed to form when gas in halos cools and undergoes further collapse to form stars. He joined IISER Mohali in 2010. MNRAS 370. We have shown that the hyperfine transition in singly ionized Helium-3 is a potential probe of the inter-galactic medium.. S. • Bagla J. S. MNRAS 405. S. James Bolton and others. 2010. 2003. Selected Recent Publications • Yadav Jaswant. 567 (2010). K. Phys. Jassal H. 185 (2002). 993 (2006). I also work on new probes of the high redshift universe.D 67. • Bagla J. 2009 (2010).. and Khandai Nishikanta. • Bagla J. 063504 (2003). . The colours show the fraction of gas in the form of singly ionized Helium.Rev.. and Padmanabhan T. These simulations are used to calculate the expected signal in the hyperfine transition of Helium-3. Khandai Nishikanta and Datta Kanan K. Efforts are underway to observe certain promising regions in the inter-galactic medium at high redshifts. S. Bagla J. MNRAS 407.Computer simulations of galaxy formation allow us to develop strategies for observations that require a large amount of time.. • Bagla J. We have used simulations to propose efficient ways to detect galaxies using emission in the hyperfine transition of neutral Hydrogen at high redshifts. and Prasad Jayanti 2006. Pictures in the top panel show a sequence where galaxy formation leads to reionization of the inter-galactic medium. Regions marked in red and orange have almost all the Helium in this form whereas in the regions marked blue there is little singly ionized Helium: it is either in the neutral or fully ionized form. we were able to demonstrate that direct detection may be easier than a statistical detection of the large scale structure. This work is being done in collaboration with Dr. Dr. Contrary to the received wisdom. Benedetta Ciardi. S. Journal of Astrophysics and Astronomy 23. Research Interests The broad research interest of Dr.Sta$s$cal Sta$s$cal Mechanics Mechanics So6 Ma7er Nonequilibrium Systems So7 Ma9er Physics Dr. . He is also interested in out of equilibrium systems. Germany and a Max-‐Planck research fellow at the Max-‐Planck Ins0tute for Intelligent Sytems in StuKgart. Dipanjan Chakraborty Dr. So6 ma7er systems are characterized by the large length and $me scales (compared to microscopic lengths) and the thermal fluctua$ons governing the dynamics of the cons$tuent macromolecules. with model examples ranging from colloidal suspensions. specifically in the problem of survival probability in non-‐sta$onary processes. resul$ng in complex structure and dynamics.D from Indian Associa0on for the Cul0va0on of Sciences. emerge at such mesoscopic length scales. The realm of so6 ma7er comprises of a mul$tude of systems with important technological applica$ons. He was an Alexander von Humboldt postdoctoral research fellow at the University of Leipizig. polymer gels and solu$ons. Chakraborty is in the physics of so6 ma7er and out of equilibrium systems. A wide range of collec$ve phenomena. Kolkata. Dipanjan Chakraborty completed his Ph. Molecualr dyanmics simula0on snapshot of a heated colloidal par0cle in a solvent. granular media to more complex systems of biological ma7er. India. Glaser. F.0 Ê ‡ PSDHwLêPSDH0L 0. with a goal to understand the rich physics at such mesoscopic length scales. Kroy. Otto. Phys. With the advent of powerful compu$ng resources.002 Ê Ê Ê ‡‡ Ê Ê Ê Ê‡ ‡ Ê ‡ Á Ê 0 2 4 6 1êT 8 10 0. E 85. V. Kirchgeßner.15 0. Giesen. B. Cichos and K.0 3. • D. M.5 Ê ‡ 1. such large scale par$cle based simula$ons are becoming increasingly popular.0 2. Rings.20 0.M.006 0. 053012 (2012). J. Chakraborty and K. Chakraborty. D.10. Phys. 051101 (2012). D. E 82. Lauter. Chakraborty Large Scale Simula@ons: Microscopic simula$ons of so6 ma7er and out of equilibrium systems provides a wealth of informa$on as to how macroscopic dynamics emerge from the microscopic degrees of freedom. Gnann.008 5. 60009 (2011). • D.) 96(6). Glaser. • J..0 0.10 0. K. R.0 10 Á · ÁÁ ÁÁÁÁ ÁÁÁÁ Á ÁÁ ÁÁ Á ÁÁ ···· Á ÁÁ ······ Á ··· ·· Á · ··· Á ·· ÁÁ · · ÁÁ · -1 Á tn ÁÁÁ···· Á · Á ··· · Á · Á Á ÁÁÁÁÁ ·· Á · Á · Á · · ·· ··· · ÁÁ ÁÁÁÁ ··Á · tn-1 · · · 0. Chakraborty. Rings. New Journal of Physics 14.01 Ê ‡ Ê Ê ‡ ÊÊ Ê‡‡ ‡ ‡ ÊÊ ÊÊ ‡Ê ‡‡‡‡Ê ‡‡Ê ‡Ê Ê ‡Ê ‡‡Ê 0. Rev. • D. Phys. Merkel and M. Rev. The research ac$vi$es of Dipanjan strongly build on large-‐scale coarse-‐grained simula$ons of so6 ma7er systems.30 Ê Xy\ XVy \ 0. EPL (Europhysics Lett. Hoffmann. D. 031112 (2009). Rev. I.1 1 7.50 Á Á Ê Ê ‡ ÊÊ Ê Á Ê Á ÊÊÊ Á ÁÁ ÁÁ Á Á Ê ÁÊÊ Ê Á Á Ê Ê ‡ 0. 046224 (2010).1 1 wt 1êT Research in pictures: a collage of research interests of Dr. Chakraborty. . F. Selected Recent Publications • D. Degawa.N.01 100 0. Kroy. E 79. Chakraborty.004 Á Á Ê ÊÊ Á Á 0.0 1. Kroy. He joined the institute in 2012. Bose National Center for Basic Sciences. The cell is an active dynamical medium.Soft and Biological Matter Dr. Monte Carlo) to investigate the dynamics of systems ranging from the cell membrane and the cell cytoskeleton to polymers and colloids in confinement. We also study the response of cytoskeletal filaments to exteternal perturbations. He has done postdocs at University of Oxford and University of Sheffield. We use an active hydrodynamics approach for the coupled dynamics of these filaments and the motor proteins to determine the organization of molecules on the cell surface. two MS students and one BS student. Chaudhuri completed his PhD from S. Research Interests The aim of our group is to understand the physical properties of biological and soft condensed matter systems that are driven out of equilibrium. Currently the group has one PhD student. which is driven out of equilibrium. It is subject to active stresses arising from a meshwork of filaments (cell cytoskeleton). A. . India. Hydrodynamics) and computational method (Molecular Dynamics. Bangalore. Brownian Dynamics. India in Soft Condensed Matter Physics. We study the consequences of such organization on signalling platforms and the uptake of material by the cell. N. We use both analytical approaches (Equilibrium and Non-equilibrium Statistical Mechanics. Raman Research Institute and Indian Institute of Science. constantly generating and dissipating energy to sustain the various life processes. Abhishek Chaudhuri Assistant Professor Dr. UK. B. 8. A. 107. 064301 (2010). Sengupta and M. Lett. B. Rev. K. 14825 (2011). Chaudhuri. G. 046002 (2011). A. 266103 (2005). Mayor and M. PNAS 108. our aim is to understand the emergent properties of colloids and polymers in confinement or otherwise. Rao. . J. 95. 81. Chaudhuri and R. 238102 (2011). Biol. Phys. Chaudhuri. Cohen. A. Phys. Chaudhuri. Golestanian . Bhattacharya. when they are subjected to time dependent external drives. Phys. S. More specifically we have been studying the problem of heat transport using non-equilibrium simulations and direct numerical evaluations of current given in terms of phonon Green's function. Golestanian. Chaudhuri et al. Selected Publications A. We are also interested in studying transport properties in general. S. A. Rev. Battaglia and R. Rev.Selected pictures highlighting research theme of the group In soft condensed matter. Phys. Lett. Gowrishankar. Rao. human diseases such as diabetes and the impact of aging on immunity. NMR Metabolomics and Diffusion Studies of Nanoparticles in Biomaterials using Gradient NMR. and has set up the NMR Research Facility.jpg). both from Bruker Biospin Switzerland. Her current research interests include NMR Quantum Computing. . Kavita Dorai Associate Professor Dr Kavita Dorai is an experimental physicist working on nuclear magnetic resonance (NMR) spectroscopy. Our research in this area focuses on demonstrations of entanglement on an NMR quantum computer and reconstruction of multi-party entanglement from two-qubit tomographs. using fruitflies.eps. Dr Dorai obtained her PhD from IISc Bangalore in 2000. Research Interests NMR Quantum Computing : Quantum computers exploit the intrinsic quantum nature of particles and have the power to solve computational problems intractable on any classical computer. implementation of the quantum Fourier transform on qubit and hybrid qubitqutrit systems. After post-doctoral stints at Frankfurt University and Dortmund University Germany and at Carnegie Mellon University Pittsburgh USA.2d-hsqc. plant-insect interactions. (Note: Images to be used for NMR Metabolomics: metabolomics. beetles and plant tissue as model systems. She moved to IISER Mohali in August 2007 when the institute was established. and construction of an ensemble witness operator on an NMR quantum information processor. 400 MHz and 600 MHz. which currently houses two high-field FT-NMR spectrometers. whose research is poised at the interface of Physics and Biology. NMR Research Facility: The Dorai group maintains the NMR Research Facility at IISER Mohali. NMR Metabolomics: Metabolomics is the new kid on the `omics' block and metabolites can be used as biomarkers of environmental stress or change. protection of an entangled subspace using the quantum super-Zeno effect. she joined the faculty of IITMadras.NMR group Dr. Our research in this area focuses on plant-pathogen interactions. J. biology and medicine. Khaneja. J. A 115. 489. Yuan. Chem. to study the diffusion of gold and silver nanoparticles inside biomembranes such as lipid bilayers. Current PhD students: Shruti Dogra (jointly with Prof. S. 6543 (2011). Arvind) Navdeep Gogna (jointly with Dr Prasad) Satnam Singh Former PhD students: Begam Elavarasi (now faculty at Abdur Rahman University. Lett. Begam Elavarasi and Kavita Dorai . Chem. Reson. A 85. Zeier. Reson. TN India) Amrita Kumari (now postdoc at Shanghai University. 248 (2010). Nimbalkar. 69 (2011). • Matsyendranath Shukla and Kavita Dorai. China) M. Neves. 012325 (2012). Arvind) Harpreet Singh (jointly with Prof. Our research in this area focuses on the development of novel 2D and 3D DOSY-based diffusion pulse sequences to separate individual components of a molecular mixture. • Amrita Kumari and Kavita Dorai. Kavita Dorai and S. J. Magn. Glaser. R. • Matsyendranath Shukla and Kavita Dorai. Chem. L. 50. Magn. H. Rev. Phys. Phys. • S. and to model protein diffusion using a combination of pulsed-field gradient NMR experiments and molecular dynamics simulations.Diffusion NMR: Diffusion NMR has wide-ranging applications in physics. J. Phys. 213. 341 (2012). Scotland) Selected Recent Publications • M. . Shukla (now postdoc at Glasgow University. Begam Elavarasi. N. Many models for Dark Energy have been proposed. She was a postdoctoral fellow at IUCAA Pune and HRI Allahabad. K. the kind we are made of. . Jassal completed her PhD from Delhi University. Research Interests The observations in the last decade and a half have lead us to believe that the expansion of our universe is getting faster. H. The constraints on dark energy parameters using different observations are shown in Fig. the nature of which is unknown (The fractions of the components of the universe are displayed in Fig. we need an exotic form of matter called the dark energy. To explain this acceleration. Professor Dr. including the cosmological constant.General Relativity & Cosmology Dr. 1. H. in particular the dark energy equation of state.). The dark energy component has negative pressure unlike ordinary matter which is pressureless and radiation which has positive pressure. K. 2. Observations at present and the ones in the future are expected to throw light on nature of dark energy and in general on the cosmological parameters. Jassal Assist. which is pressureless and interacts only via gravitational forces. The most dominant component of the universe is the mysterious Dark Energy which drives the acceleration of the universe. About 24% of which is Dark Matter. She joined the institute in 2011. The rest is composed of largely unknown types of matter. I am interested in using different observations to constrain cosmological parameters. The universe has only 4% of ordinary matter. I show that there are significant differences in the way structures form (see Fig. J. 2639 (2010). Selected Recent Publications • • • • • H. H. Jassal Phys. the observable effect of these perturbations is in the Integrated Sachs Wolfe effect. Jassal Phys.I am also working on implications of dark energy on structures in the universe if dark energy itself actively contributes. T. which is zero if the universe is composed only of nonrelativistic matter and in presence of dark energy has a nonzero value. 127301 (2009). 043529 (2012). S. 083513 (2010). 123504 (2008). K. Jassal Phys. In recent work. Rev. Jassal. Rev. K. Bagla. Jassal Phys. D 86. H. K. D 79. D 81. . H. Padmanabhan MNRAS 405. Rev. Rev. K. 3) for different models and future observations should be able to rule out some of the many models of dark energy. D 78. K. I have shown that taking dark energy perturbations into account is important as these perturbations affect how normal matter perturbations grow. In particular. H. Quantum Thermodynamics: This rather novel area refers to the interplay between thermodynamics and quantum theory. exploiting Maxwell's demon to understand the role of information-theoretic ideas in thermodynamic settings. It provides the theoretical backbone to understand the functioning of miniature thermal machines and information processing devies. Johal Associate Professor Dr. Cycles in finite time are studied and effect of quantum interactions between the components of the system are investigated. Ramandeep S. . We have studied quantum heat cycles such as Otto cycle. He was Alexander von Humboldt fellow at Technical University of Dresden. and characterized its efficiency and work extraction. Some questions for reflection relate to the nature of probability in physics and the use of Bayesian inference in physical theories. He joined the institute in 2008. He did a second post-doc at University of Barcelona. The past research interests include deformed algebras. The connection between information-theoretic concepts and thermodynamics is explored.Quantum Thermodynamics Dr. generalized statistical mechanics and long-range interactions. Chandigarh. Ramandeep Johal did his PhD in theoretical physics from Panjab University. Research Interests The main research interests of the group are in the foundational issues in thermodynamics and quantum theory. Sometimes. Dissipation and irreversibility are analysed with friction-like effects in the quantum regime. we also conduct thought experiments using age-old models like Szilard engine. Germany. The techniques of quantum systems interacting with thermal environments provide a useful tool. The classical thermodynamic processes can be reformulated for quantum media. Spain. The current interests include Quantum Thermodynamics and different formulations of nonequilibrium thermodynamics. Maxwell’s Demon at work Inference and physical theory: Inference may be regarded as common-sense reasoning in the face of incomplete information. Taking thermodynamics as the substrate physical theory. Bayesian statistics and information-theoretic quantifiers play useful role. Rev. We seek to understand the interplay of subjective/objective information in the formulation and interpretation of physical theories. Techniques like maximum entropy principle. Rev. in terms of their efficiency and obtained novel correspondence with irreversible finite-time heat engines. S. The philosophical perspective central to this investigation is that prior information can play useful role to characterise uncertainty. Selected Recent Publications • P. Thomas and R. S. . we estimate the performance of idealized heat engines with incomplete information. Phys. 041118 (2008). (2013). A: Math. E 77. Johal. Thomas and R. Rev. E 83. S. 031135 (2012) • G. 46. 061113 (2010). S. Phys. Aneja and R. in general. Johal. E 82.E. • G. 365002 (2013). Allahverdyan and G. Theor. Mahler. Phys. • R. A. J. Johal. Phys. Johal. he was a visiting fellow at Department of Theoretical Physics. exact transfer matrix. Brownian Dynamics. Rajeev Kapri Assistant Professor Dr. in Physics from Homi Bhabha National Institute (HBNI) Mumbai.D. Monte Carlo and molecular dynamics simulations. Soft Matter Physics Dr. Rajeev Kapri was a doctoral scholar at Institute of Physics Bhubaneswar and obtained his Ph. Research Interests His broad research interests are in developing simple models of complex biological processes and study them by using tools of statistical physics like generating functions.Statistical Mechanics. India. Tata Institute of Fundamental Research (TIFR) Mumbai. Before joining the institute in 2009. . Lett 98. Rev. Euro Phys. Selected Recent Publications • Rajeev Kapri. • Rajeev Kapri and D. P. J. • Rajeev Kapri. Dhar. 1051118 (2009). Phys. Singh. E 80. Phys. 130. (ii) the behavior of particles or fluids on a fluctuating membrane. . Rajeev Kapri and S. Phys. and. Chem. (iv) the behavior of polymer in a confined environment. (iii) hysteresis in DNA. Rev. 60004 (2012). Sinha. • K. E 86. 14510 (2009).Pictures gallary from Femto-laser Lab His recent interests are in exploring: (i) the surface-polymer interaction via external forcing of the polymer. 041906 (2012). leading to the ferroelectric behavior. Pressure driven high-‐Tc mul?ferroicty in CuO: In a recent work. Prof. Kumar completed his PhD from Harish-‐Chandra Research InsEtute. Currently. Leiden University in The Netherlands. Sanjeev Kumar Asst. disordered superconductors. Magneto-‐electric phase diagram of CuO . we predict that cupric oxide (CuO) under pressure can be a room-‐temperature mul7ferroic with strong coupling between magne7c and electric order parameters. India. the group has two PhD students and two MS students. The study combines ab-‐ini7o DFT calcula7ons. India in 2011. Beyond 40GPa CuO is predicted to be the first room-‐temperature spin-‐spiral mul7ferroic. He was awarded the Ramanujan fellowship by DST. The ferroelectricity in this material is driven by spin-‐spiral states. Our calcula7ons predict that under pressure . and the spin-‐ orbit coupled systems. and Monte Carlo simula7ons of the resul7ng magne7c Hamiltonian. Allahabad. Research Interests The group is interested in the study of correlated and disordered quantum systems using a combina7on of theore7cal and computa7ons methods. S. spin and orbital degrees of freedom in microscopic model Hamiltonians. Our research theme is the search for unconven7onal ordering of charge. mul7ferroics. the non-‐collinear magne7c state is stable to high temperatures. He held post-‐doctoral research posiEons at the University of Augsburg in Germany.Correlated and Disordered Electron Systems Dr. The specific topics of current interest are. and their consequences for macroscopic physical proper7es of the relevant materials. frustrated i7nerant magne7sm. & DST Ramanujan Fellow Dr. and IFW Dresden in Germany before joining the insEtute in 2010. Lett. Phys. J. Kumar et al. Lett. Therefore. such as superconduc7vity. M. (2010). Venderbos. J. Kumar and J. Rev. M. Nature Comm. Daghofer. Rev. We have recently studied the effect of site and bond disorder on s-‐wave superconduc7vity using Bogoliubov-‐ deGennes self-‐consistent approach. Rev. Phys. Kumar. Brink. v. Brink and S. DistribuEon of pairing amplitudes Selected Recent Publications • X. understanding the effects of disorder on various long-‐range ordering phenomena is a very important and ac7ve field of research. 105. Brink and S. 107. Phys. S. Venderbos. d. We show that a realiza7on of the famous Haldane state in honeycomb laOce is realized in this system with electrons coupled to localized magne7c moments on checkerboard laOce. Lett. This introduces disorder in the system arising from the random loca7ons of the dopant ions. giant magnetoresistance. v. Daghofer. Blaha. Phys. J. Rocquefelte. P. 076405 (2011). 026401 (2011). Giovannetti. Schwarz. 166405 (2012). d. Rev. v. . Kumar. 109. d. 216405. S. Brink. anomalous Hall effect etc. appear upon doping some parents stoichimetric material with electrons or holes. K. on a 2D checkerboard laOce we find that magne7c moments organize in a way that introduces fic77ous magne7c fields for the electrons and leads to a graphene-‐like electronic dispersion. • • • • (in press).Selected pictures highligh7ng research theme of the group Frustrated iteinerant magnets: In recent studies we have shown that the compe77on between ferromagne7c double-‐exchange and an7ferromagne7c superexchange on geometrically frustrated laOces stabilizes exo7c magne7c order. Lett. and presently we are studying the effect of spin-‐dependent disorder on superconduc7vity. G. S. v. d.. For example. Kumar and J.. MagneEc flux phase on checkerboard Disordered superconductors: OSen the most interes7ng electronic proper7es. 106 . J. USA and Argonne national Laboratory. ferromagnetism. Chicago. multiferroicity etc.Condensed Matter Physics Dr. Mumbai in condensed matter physics. Argonne. He joined the institute in 2012. Ferroelectric Lithography on PZT using an AFM tip Particle ejection from a hard superconductor due to pulsed laser irradiation . The group also investigates the physics of the magnetic vortices in unconventional superconductors by magnetic force microscopy at low temperatures and in magnetic fields. ferroelectricity. Using these techniques one can also probe the ferromagnetic and ferroelectric materials. He has done two postdocs at Northwestern university. USA. Research Interests: The principal research interest of the group is the investigation of systems exhibiting novel physical phenomena like superconductivity. using scanning probe microscopy and transport spectroscopy at low temperatures and high magnetic fields. Goutam Sheet Ramanujan Fellow Dr. In superconductors. the interest is to study the nature of the superconducting gap(s) by point-contact spectroscopy and scanning tunneling microscopy at low temperatures. Goutam Sheet completed his PhD from Tata Institute of Fundamental Research. K. S. Koshelev. and V. J. E. Phys. Crabtree. G. 012601 (2012). J. Welp. 105. A. C. A state of the art scanning tunneling microscope for low temperature and high magnetic field applications is being designed and fabricated in house. W. Hellstrom. Alexandra R. 101. Eom. Erik J. • Goutam Sheet. M. C. Offerman. Rev. D. Kwok et al. J. Manan Mehta. Appl. Phys. Jiang. 104309 (2010). Y. 259701 (2006). Chad M. Folkman. W. Lett. App. and Venkat Chandrasekhar. Rev. D. Chang-Beom Eom. E. 96. Claus. • Goutam Sheet and Pratap Raychaudhuri. Chaparro. . A. 107. G. H. C. S.Plasma formed on the surface of copper target during sputtering in the device lab Human red blood cell imaged by AFM The lab dedicates significant amount of time developing new measurement techniques. Lett. Lee. Weiss. Dikin. A. Fang. Phys.. Chandrasekhar Phys. E. W. U. Sheet. Jia. 167003 (2010). B. The final design of the STM head is shown below: Selected Recent Publications • L. Cunliffe. Rzchowski. Bark. Kirk. M. Lett. • Goutam Sheet. Besides. Kumar. These pulses can be further compressed to produce phase-stabilized few cycle sub 7fs laser pulses. Attosecond Physics: We are working to setup an Attosecond beam line to produce attosecond XUV pulses of light (1as=10-18s) using high harmonic generation (HHG). P. the coherent control of electron dynamics is Theoretically studies by numerically solving TDSE. attosecond physics. Kansas State University. White light filamentation by fs-pulse . P. nonlinear optics using intense pulses. pump-probe measurements and in biology. We are studying various phenomenon like time-resolved abalation. He joined the institute in 2009. K. Ultrafast optics: Interaction of fs-pulses with various materials is an active research area. K. P. We study applications of these pulses in laser-matter interaction.Femto-Laser Laboratory Dr. Research Interests The lab houses a state-of-the art femtosecond laser system that produces intense ultra-short IR pulses with 2mJ energy per pulse at 1 kHz repitition rate. Singh completed his PhD from University of Rennes1. USA. Application of these coherent XUV pulses for pump-probe experiments are envisioned. France in laser Physics. Gopal Verma. Postdoc: Dr. Current PhD students: Bhupesh Kumar. He has done two postdocs at Max Planck Institute Dresden and JRM Lab. Singh Ramanujan Fellow Dr. 023001. Phys. Kapri.046219 (2011). Phys. Singh et al. 60004 (2012). Singh and Sudeshna Sinha. (2010). Singh. Kamal P. Diffraction by twisted spider silk Selected Recent Publications • • • • Gopal Verma. R. Singh. 110. • Kamal P. . James Nair. Rev. Phys. Sudeshna Sinha. 104. This sheds light onto nature of light-interface phenomenon that may find potential applications. Lett. The interaction of ultrashort laser pulses to precision abalation biological materials is also considered. Kamal P. Lett. we demonstrated bending of fluid-fluid and air-fluid interfaces by radiation pressure in total-internal reflection geometry. 98. A. Kenfack and Kamal P. Rev. 046224 (2010). Rev. Rev. 079401 (2013). Kamal P. Phys. E 83. E 82.Pictures from Femto-laser Lab Bending fluid-interfaces with light: Recently. Lett. Biophotonics and Biophysics: Applications of the femtosecond and CW lasers to study biological systems are explored. Singh. Euro Phys. We have exploited diffraction based optical techniques to probe long-range correlations in the biophotonic architecture of transparent insect wings and spider silk systems. A measurement performed on the state of one particle results an immediate influence on the state of other particle – a phenomenon known as nonlocality in quantum mechanics. no macroscopic object has observed yet to be present at more than a one place at a given instant of time. Mandip Singh Bose Einstein Condensation & Photons Assist. atoms. Concept of reality. Professor Research Interests Quantum mechanics is a broad subject that explains how photons. However. To explore fundamental features of quantum mechanics the realization of two laboratories is in progress. Entanglement can be considered as a superposition in which constituents can be separated. From foundational point of view quantum superposition and entanglement are counterintuitive aspects of the microscopic world. observation in quantum mechanics and implication of quantum mechanics at macroscopic level are the topics which are not yet completely explained.Quantum Research Laboratory Dr. Quantum mechanics allows quantum superposition of macroscopic objects and even of living matter as argued by Schrodinger through a cat paradox. Equipped with edge cutting research technology the labs will explore the quantum world through experiments based on Bose Einstein condensation and photons. According to quantum superposition principle. . a particle can be present at more than a one location at a given instant of time. Modern day technology is based on practical implications of quantum mechanics. When two entangled particles are separated in space their entanglement remains intact. molecules and subatomic particles work. Integration of engineering & technology with advanced experimental techniques of physics is an essential component for research innovations. M. .Extended cavity diode lasers of line width 100 kHz and mode hop free tuning range 50 GHz for laser cooling of neutral atoms. Physics Education: Teaching physics through demonstration experiments. symmetries. Critical temperature which is of the order of 0. Those atoms which are not condensed expand faster during free fall while a Bose Einstein condensate expands much slower and anisotropically during free fall. Optics Express. Bose Einstein condensation experiment: Bose Einstein condensation occurs when wave packets of individual bosonic atoms overlap as a result atoms in the condensed state are governed by a single macroscopic wavefunction. Anisotropic expansion of cold atoms is a signature of Bose Einstein condensate. Extended cavity diode lasers will cool atoms to a mK temperature range in a magneto optical trap. 2600 (2009). Temperature of ultracold atoms is calculated from rate of expansion of atomic cloud during free fall. M. M Singh. In this context. Selected Recent Publications: • J. Kotyrba & A. Phys. Rev. Polarization gradient cooling will produce a temperature of about 40 µK. • Mandip Singh. 032115 (2012). geometry and simplification of a complex phenomenon to root principles are the key concepts in physics education. Ebner. Kofler. Zeilinger. A 86. Bose Einstein condensation experiment consists of an ultrahigh vacuum chamber where condensate will be produced in a magnetic trap. Keller. analogies. Further cooling below Doppler limit will be realized through a polarization gradient cooling. M. 17.1µK will be realized through an evaporative cooling using a radio frequency pulse. Bose Einstein condensate will be observed through a technique called absorption imaging where a resonant laser pulse is incident on a free falling condensate and scattered light from the condensate is imaged with a lens on an EMCCD camera. Critical condition for Bose Einstein condensation implies atomic wavepackets must be overlapped in momentum space as well as in real space simultaneously. a paper resulting from work on physics education has been communicated to a journal. He was awarded the Ramanujan Fellowship by DST. Prof. Research Interests: • Single Crystal Growth of correlated materials • Magne7cally frustrated materials • Quantum Spin systems • Unconven7onal Superconduc7vity • Charge/Spin Density Waves Recent Highlights: Realiza7on of the Heisenberg-‐Kitaev model in honeycomb laFce iridates A2IrO3 (A = Li. Yogesh Singh Asst. before joining the ins<tute in 2011.Novel Materials Group Dr. & DST Ramanujan Fellow Dr. Iowa. Na) • • • Strong Magne?c Frustra?on Unconven?onal Zigzag-‐order for Na2IrO3 Li2IrO3 close to a quantum spin-‐liquid state Crystal and magne<c Structure of A2IrO3 . Germany. USA and the University of GoeNngen. Yogesh Singh completed his PhD from Tata Ins<tute of Fundamental Research Mumbai. He held postdoctaral research posi<ons at the AMES lab. India in 2011. . Kolmogorov. Z-‐H. LeL. 127203 (2012). Rev. 127204 (2012). A. W. 220403 (2011). J. Phys. • R. Mazin. Singh et al. Y. • Y. Singh et al. Bozin. E. Y. Rev. T. G. Singh et al. Singh et al. LeL.. Gretarsson. . Levy. 108. LeL. 076402 (2013). Y. Singh et al. Liu. 266406 (2012).-‐G. C. S. P. Choi. Zhu. R. Y. Phys.. Clancy. Berlijn. Comin. Phys. Yin. Phys.Research in pictures Mul7-‐gap Superconduc7vity in the layered Boride OsB2 • • Superconduc?vity below Tc = 2. B. Ku. Rosen. Gretarsson. W. T. Blundel. Rev. Liu.1 K Fermi-‐surface made up of one tubular and two ellipsoidal sheets Selected Recent Publications • H. • S. P. Lancaster. A. Hill. Rev. 110. Radaelli. B 83. Ludbrook. I. Tsvelik. J. Coldea. J. H.. LeL. 108. 109. Phys. Rev.. X. • X. Y-‐J Kim. Veenstra. Research Interests Control of Chaotic Systems: This group is interested in strategies to control the dynamical behaviour of complex systems. Synchronization of Complex Networks: We work on problems of synchronization in a wide variety of dynamical networks. and demonstrated its success in simulations. She has been a member of the physics faculty of the Indian Institute of Astrophysics. including most recently on time-delayed systems. Lastly. We have also proposed distributed adaptive schemes capable of stabilising complex spatio-temporal patterns in extended systems. ranging from epidemic spreading models to networks of neurons and coupled cell pathways. on pattern formation in the network. Chennai (1996-2011). we have also introduced adaptive “anticontrol” schemes for enhancement and maintenance of chaos.Nonlinear Dynamics & Complex Systems Dr. . We have also realized the idea in several experiments. such as for the case of neuronal spiking and smart matter applications. Indian Academy of Science Prof. Sudeshna Sinha Fellow. She joined IISER Mohali in 2009. In particular we have introduced the method of threshold control. Mumbai. This has relevance in contexts where enhanced chaos leads to improved performance. Most recently. we have focused on investigating the influence of dynamic and quenched random connections. Sudeshna Sinha completed her PhD from the Tata Institute of Fundamental Research. Bangalore (1994-1996) and The Institute of Mathematical Sciences. such as mixing flows in chemical reactions. we find how noise is crucial to the emergence of robust logic behaviour. is studied in systems ranging from nano-mechanical oscillators to electronics circuits. Currently. Postdoc: Soma De Work on Synthetic Gene Networks as potential Flexible Parallel Logic Gates: Cover of Europhysics Letters (2011) . This paradigm has been realized in many electronic circuit experiments. called Logical Stochastic Resonance. and forms the basis of a reconfigurable chip design. which is expected to yield a dynamic computer architecture more flexible than the current static framework. Anshul Choudhary and Ankit Kumar. This phenomena.Space time simulation of complex dynamical networks Dynamics Based Computation: In recent years we have proposed the novel concept of chaos computing. For instance. Current PhD students: Vivek Kohar. we are exploring this idea in a genetic ring oscillator network with quorum sensing feedback Interplay of noise and nonlinearity: The constructive effect of of noise in enhancing performance is a focus of recent work. Still a nano-scale beam Shows a significant change in quality Factor with temp. What is NEMS ? Why Study NEMS @ low temp? At T < 4. Boston working on 2-D electron systems. Out activities revolve around i) A state of the are Ultra low temperature lab that can reach thermodynamic temperatures ~ 10 mK and ii) A nano-scale Fabrication facility that includes tools like e-beam lithography. We will be able to make similar and even more complex devices at IISER A 5micron long 180 nm wide Au beam Data by PI from NottinghamResponse of the beam@ 20 mK & 600 mK .2 K almost everything except Liquid helium freezes. the lab. Ananth Venkatesan completed his PhD in Physics from Northeastern University. Ananth Venkatesan Ramanujan Fellow Dr. U. Research Interests We study mesoscopic devices like nano-electromechanical systems(NEMS) and 2-D electron gas systems (2-DEGS) at ultra low temperatures. He did a Post-Doc un UBC.Nano-Scale Mechanical and Electronic Systems @ Ultra-low Temperatures Dr. two MS students and a Post-Doc who is joining us shortly. Canada followed by a Post-Doc at the University of Nottingham.K. has two PhD students. a plasma etch system. Currently. Shown below is the time domain Response of ananoscale gold beam at 20 mK and 600 mK A nanoscale guitar string? A Super-conducting material Sample fabricated at University of Regensburg by the PI. M. Phys. Lett. Mellor. and J. Frolov. M J Patton. Lett. M. Rev. Venkatesan. K.J Lulla. In reality higher frequency devices have low Q-factor making it difficult to measure anything sensible We try to understand the low temperature quantum dissipation scenario and also engineer high –Q devices. 116802 – ( 2009) • S. and T. New J. A. Rev. J. A Venkatesan. Folk. Owers-Bradley Phys. Shashkin. W. M. J. ______ B =10T 3 2 T =200mK 1 -120 -100 -80 -60 -40 Gate voltage (mV) The data shows quantized conductance and spin splitting in B fields. C. M.a C b Image Gallery from the low temp lab a) Microwave waveguide circuits b)A Vacuum probe (c)The workhorse of our lab a dilution fridge that reaches 10m K It is interesting to note that mechanical propeties change significantly below 4. 96. R. R. J. We are also interested in piezo Electric behaviour to produce Hybrid NEMS devices. V. A. Armour. Venkatesan. Klapwijk Phys. A. • S. S. D. 14 113040 (2012 ) • A. 2-DEGS & other electronic systems: 6 5 250n m Width g (e2/h) 4 A 250 nm wide Split gate defines a ballistic 1-D Conductor on a 2-DEG ______ B = 0T In 2-DEGS we are specifically Interested in spin current transport And also electronic correlations. The typical temperatures of 10 mK we can reach in a dilution fridge (like the one if (c) of the gallery in the regime hw >> KBT one can hope to see macroscopic quantum phenomena. Data by PI when at UBC Selected Recent Publications • K. J. 046409 ( 2006 ) . A D Armour. and W. Kravchenko. Sakr. In principle NEMS Devices vibrate at high frequenices from RF to Microwave regime. B 81. Lulla. C J Mellor and J R Owers-Bradley. R B Cousins. Rev. Wegscheider Phys. 073410 ( 2010) .2K. 102. Anissimova. A. Patton. Yu. Venkatesan. A. A. P. Yogendran completed his PhD from Tata Institute of Fundamental Research.String Theory Dr. He has been a postdoctoral fellow at HRI. P. An effective analogy should capture the unitarity of the process of burning coal at the same time as incorporating the salient features of black hole thermodynamics which might shed some light on the information paradox in black hole physics. An enduring puzzle in quantum gravity has been to identify the degrees of freedom that "constitute" a black hole. The current objective in this program is to explore how gapped fermions make their appearance in these systems. He joined the institute in 2009. Cquest Korea and HIP Finlend. My research has been focused on one system which exhibits superfluidity due to the spontaneous breaking of a global symmetry. I am trying to build an analogy in a manner that will hopefully enlarge the difference between a burning lump of coal and a black hole. Allahabad. . implying that perturbative calculations often give misleading results. K. Yogendran Assistant Professor Dr. there has been a flurry of activities in applying ideas originating from string theory to systems that involve strong interactions. Research Interests In recent years. K. Mumbai. S. Keranen. Keski-Vakkuri.P. Keski-Vakkuri. • V. Keranen. Park. We are therefore studying the hydrogen atom from this perspective at varying levels of sophistication (as part of a student summer project) which casts some light on the difference between bound and scattering states. P. D 80. • V. 065003 (2011). Nowling. K. S. Keski-Vakkuri. C. • V. Yogendran. Yogendran Phys. Yogendran. Yogendran.A holographic dark soliton: The soliton seen in the lab is (roughly) the z=0 slice of this picture In course of building the analogy. D 81 126012 (2010) . A future direction would be to explore the Kohn Sham theorems from the point of view of entanglement entropy. S. K. J. we are led to understand bound states as entangled states of their multiparticle quantum constituents. E.Rev. Keranen. Astrophys. E. Phys. E. • V. Rien van de Weygaert. Keranen. 122 (2012). D 81. Yogendran. Nowling. K. K. Selected Recent Publications • P. S.Rev. K. E. New J.P. Nowling. 755. 13.Phys. Nowling. Keski-Vakkuri. Phys. 126011 (2010).Rev. 121901 (2009). . Chingangbam. P.P. . Sinha. Jassal. K. Mandip Bose Einstein Condensate (BEC) and Photons Lab Dr. Sheet. Rajeev Statistical Mechanics and Soft Matter Physics Dr. Sudeshna Nonlinear Dynamcis and Complex Systems Dr. Chakraborty. Singh.Physics Faculty by Research Area Prof. Ramandeep Quantum Thermodynamics Dr. Goutam Condensed Matter Physics Dr. Jasjeet Cosmology Dr. Johal. Dorai. Yogesh Novel Material Group Prof. Sanjeev. Ananth Dr. Kamal Femtosecond Laser Lab Dr. Venkatesan. Dipanjan Soft Matter Physics Dr. Arvind Quaqntum Information Prof. P. Kavita Nuclear Magnetic Resonance (NMR) Lab Dr. Choudhary. Mahajan. Laser Physics Dr. Singh. C. Yogendran. G. Kapri. Kumar Correlated and Disordered Electron Systems Prof. Bagla. Singh. Abhishek Soft and Biological Matter Dr. Harvinder General Relativity and Cosmology Dr. Nanoscale Mechanical & Electronic systems at ultralow Temperature String Theory . IISER Physics Faculty .