28-01-2013 At 04:00:00 PM
Speaker: Prof. S. D. Mahanti, Department of Physics and Astronomy, Michigan State University, USA
Category: Colloquium
Venue: Lecture Hall
The introduction of the concept of topological insulators (TI) has added anew dimension to our understanding of the nature of the insulating state.These novel insulators differ from the well known ones (sometimes referredto as trivial insulators) such as band insulators, Mott insulators,covalent insulators, Anderson insulators in a fundamental way. All theseinsulators including the TIs have bulk band gaps and surface states whichcan carry current. But in TIs the surface states are topologicallyprotected, gapless and have striking spin texture. The surface stateelectrons possess an intrinsic chirality which enables the propagation ofconduction electrons where spin is locked to momentum and backscatteringevents are suppressed. This remarkable surface electronic structure arisesfrom spin-orbit interaction and time reversal invariance, resulting in theformation of odd number of massless Dirac cones in the single particleenergy dispersion. The charge transport through these topologicallyprotected surface states is dissipationless. After a review of theseexciting features of the TIs I will discuss some recent experimentalobservations (Angle Resolved Photo Emission, Scanning TunnelingMicroscopy, Nuclear Magnetic Resonance etc) and their understanding from atheoretical perspective within single particle electronic structure.
31-01-2013 At 04:00:00 PM
Speaker: Prof. Jogesh.C. Pati, SLAC, Stanford University, USA
Category: General Seminar
Venue: Lecture Hall
05-02-2013 At 04:00:00 PM
Speaker: Dr. Joydeep Chakrabortty (PRL, Ahmedabad)
Category: TPSC HEP Seminar
Venue: Lecture Hall
After giving a brief introduction to the Standard Model I will point out theimpact of the recent results -- announcement from ATLAS & CMS, large theta(13). Then I will discuss the Beyond Standard Model (BSM) Physics. I will give two examples: Grand Unified Theory (~ 10^16 GeV ) and low scale (TeV) models as BSM candidates. I will try to convey how the very high scale models can be phenomenologically interesting in the LHC Era.
08-02-2013 At 04:00:00 PM
Speaker: Prof. Bidhan Candra Bag, Department of Chemistry, Visva Bharati, Santiniketan, India
Category: TPSC Seminar
Venue: Lecture Hall
Recently we have studied the non-linear dynamics of a charged particle in x-y plane in presence of a magnetic field. Velocity dependent coupling through magnetic field between motion along x and y directions may induce chaos (stochasticity) in the deterministic system. If the applied magnetic field is time dependent, then for any initial condition dynamics is chaotic. We have qualitatively accounted for the chaotic dynamics based on Hamiltonian description of motion in terms of action and angle variables. Our study also shows that time dependent magnetic field (TDMF) can induce chaos even in a linear system. It implies that dynamics of quantum dot in presence of a TDMF may be chaotic. For the linear system we have determined condition of chaos. Finally, appearance of chaos in the linear system clearly indicates that in presence of a time dependent magnetic field chaotic dynamics of a charged particle in real (nonlinear) system is a universal feature.
11-02-2013 At 04:00:00 PM
Speaker: Prof. Sudhir Vempati, IISc, Bangalore
Category: TPSC HEP Seminar
Venue: Lecture Hall
The recent disovery of the light higgs mass at 125 GeV and the direct searches for supersymmetric particles at the LHC put constraints on the various supersymmetric extensions of the Standard Model. I review the status of popular supersymmetric breaking mechanisms and present some of the ideas we have been exploring in the light of these results.
12-02-2013 At 04:00:00 PM
Speaker: Dr. Arnab Kundu, University of Texas
Category: General Seminar
Venue: Lecture Hall
13-02-2013 At 04:00:00 PM
Speaker: Dr. Arnab Kundu, University of Texas
Category: HEP Seminar
Venue: Lecture Hall
15-02-2013 At 04:00:00 PM
Speaker: Dr.S.B. Ota, IOP, Bhubaneswar
Category: Solid State Physics Colloquium
Venue: Lecture Hall
The 2011 APS March meeting was held in Dallas, USA during 21-25 march. It commemorated 100 years of superconductivity. Observation of vortex lattice related anomalies in polycrystalline YBa2Cu3O7-x near Tc was presented in the meeting.
18-02-2013 At 04:00:00 PM
Speaker: Prof. Sudhansu S. Mandal, IACS
Category: Colloquium
Venue: Lecture Hall
19-02-2013 At 04:00:00 PM
Speaker: Dr. Sayantani Bhattacharya, ICTS, TIFR, Bangalore
Category: HEP Seminar
Venue: Lecture Hall
20-02-2013 At 04:00:00 PM
Speaker: Prof. Arunava Chakrabarti, University of Kalyani, West Bengal
Category: TPSC Seminar
Venue: Lecture Hall
We shall discuss how to engineer wave function delocalization in disordered systemsmodeled by tight binding Hamiltonians in d > 1 dimensions. Exact analytical results willbe presented for the case of a two legged ladder network infinitely large along the x-axis,revealing how it can finally be used as a switching device. The results persist even whenthe ladder expands in the transverse direction, making a journey towards a real twodimensional system. The study gives rise to the possibility of designing disorderedpotentials that might work as band-pass filters for quantum waves, such as matter wavesin optical lattices.
27-02-2013 At 04:00:00 PM
Speaker: Dr. Ritam Mallick, PDF, IOP
Category: General Seminar
Venue: Lecture Hall
28-02-2013 At 04:00:00 PM
Speaker: Dr. Vijay Kumar, Sant Longowal Institute of Engineering & Technology [A Govt of India Institute esta
Category: Experimental CMP Seminar
Venue: Lecture Hall
The present work reports the two step electrochemical synthesis of processfor the fabrication of different metal conducting polymer composites (viz.Au-polyaniline, Au-polypyrrole and Ag-polypyrrole). Initially, conductingpolymers such as polyaniline and polypyrrole were electrochemicallysynthesized on different substrate using a chronopotentiometery techniquewith optimized process parameters. The synthesized conducting polymerfilms act as working electrode for the decoration of submicron metalparticles on the surface of conducting polymer films through acyclicvoltammetry (CV) technique. Later, these composite films wereirradiated with gamma and under high vacuum (~5×10-6 Torr) at roomtemperature with different heavy ion beams radiations at various fluencesranging. The composites are characterized by scanning electron microscopy(SEM), micro-Raman and X-ray diffraction spectroscopic techniques beforeand after irradiation. Raman studies revealed that structure of the filmsbecame disordered after irradiation, which was also observed in SEMimages. Detailed Raman and XRD spectroscopic analysis had been presentedand SEM investigations showed that the craters were formed in the filmswith increase of ion fluence. The present investigations explore theapplicability of irradiated composite films for sensor applications.
28-02-2013 At 12:00:00 PM
Speaker: Prof. R.Palit, TIFR, Mumbai
Category: General Seminar
Venue: Lecture Hall
01-03-2013 At 04:30:00 PM
Speaker: Dr. Sibashisa Dash, University of Milan, Italy
Category: Experimental CMP Seminar
Venue: Lecture Hall
The understanding of Transition metal (Mn) impurity on semiconductingsurface have opened a wide scope of investigation based on the localstructure, hybridization effect, electronic properties and magneticordering occurring on the surface/interface of the system. The preparedsurface/ interface has been probed in-situ by X-ray photoemission (XPS),X-ray absorption (XAS) and the resonant photoemission (ResPES)spectroscopies along with the parameterized configuration integration (CI)models to calculate the Mn spectral weight in core-level and valence bandphotoemission. Presence of electron correlation has been evident by anintermediate state in the process of photoemission channel. Change of thelineshape due to the transition from an overall N – 1 electron final state(RRAS channel) to an N -2 electron final state (normal Auger channel) isevidenced by the analysis of the experimental data, which also allowed theratio to be tracked between charge delocalization and core-hole timescales as the photon energy is tuned across the Mn L3 edge [1].This can beused as an analysis technique for presence of electron correlation intransition metal based inorganic system. In addition to this, angleresolved photoemission spectroscopy (ARUPS),a powerful technique has beendone for experimental band mapping to detect the evolution of surfacestates below the Fermi energy or Mn derived state crossing the Fermi edgeof the Mn:Ge(111) sample [2]; as compared to the calculated band structureby Density functional theory using LDA[4]. In the second section adescription will be given on the cation diffusion and hybridizationeffects at the Mn-GaSe(0001) interface probed by soft X-ray electronspectroscopies[3]. In all the above systems, magnetic properties have beenrevealed as characterized by SQUID magnetometer.References1. Tracking the excitation dynamics in the Mn:Ge(111) metallic interface by resonant electron spectroscopy, L. Sangaletti, *S. Dash*, A. Verdini , L. Floreano, A. Goldoni, G. Drera, S. Pagliara, A. Morgante, J. Phys.: Condens. Matter 24 (2012) 2355022. Angle resolved UV Photoemission study on Mn:Ge (111) surface, *S. Dash*, L Sangaletti, L petaccia et. al. in preparation3. Cation diffusion and hybridization effects at the Mn-GaSe(0001) interface, *S. Dash*, G. Drera, E. Magnano, F. Bondino, P. Galinetto, M.C. Mozzati, V. Aguekian, and L. Sangaletti to be submitted4. First-principles characterization of ferromagnetic Mn5Ge3 for spintronic applications, S. Picozzi and A. Continenza, A. J. Freeman
01-03-2013 At 03:00:00 PM
Speaker: Dr. Bindusar Sahoo, (NIKHEF)
Category: General Seminar
Venue: Lecture Hall
In the last couple of decades a theory has been developed byVasiliev to consider interacting theories of fields with spin greater than2 which is known as higher-spin gravity. This theory has received a lot ofattention recently in the context of AdS-CFT correspondence. The theory invarious dimensions is conjectured to be dual to well known conformal fieldtheories in the boundary. In the light of this recent development, we willdiscuss the higher-spin analogue of topologically massive gravity in threedimensions, which we call topologically massive higher-spin gravity. Wewill start with a brief introduction and motivation to consider higher-spintheories. This will be followed by a brief introduction and overview ofcurrent results in higher-spin theories and topologically massive gravity.This will be followed by our work on topologically massive higher-spingravity. We will discuss various semi classical as well as quantum resultsof the theory considered by us.
13-03-2013 At 04:00:00 PM
Speaker: Prof. Anindya Datta, Calcutta University
Category: TPSC HEP Seminar
Venue: Lecture Hall
If the recently discovered new boson is confirmed to be a Higgsboson, thenstability of the electroweak vacuum in a minimal model with a universalextra dimension (mUED) willrequire a much lower cutoff for the theory than has been envisaged earlier.We show that this lowcutoff leads to important changes in much of the mUED phenomenology studiedtill now. In particular, prospects for LHC searches for n = 1, Kaluza Kleinstates are ratherlimited if conventional search strategies are used. We propose some newmethods which can overcome these difficulties.
18-03-2013 At 04:00:00 PM
Speaker: Prof. Naba Kumar Mondal, TIFR, Mumbai (Spokesperson of INO)
Category: Colloquium
Venue: Lecture Hall
Neutrinos, “the most tiny quantity of reality ever imaginedby a human beingâ€, as quoted by its co-discovererFrederick Reines, never ceased to puzzle physicists.Wolfgang Pauli introduced neutrino in 1930 as a desperateremedy to save the “law of conservation of Energyâ€. It thentook twenty seven long years to find the first experimentalevidence for its existence. The reason for this long wait isits extreme reluctance to interact with matter. Neutrino canpass through the earth, the sun or other astrophysical objectswithout much interaction. They interact at the best onlyone time over one billion in the huge apparatus built to detectthem. This particular property of neutrino however turnsout to be a blessing in disguise as it opens up a new windowto look at the interior of sun and other astrophysical objects.Over the last several decades, dedicated neutrino experimentsaround the globe have looked for neutrinos from the sun, fromouter space, from interior of the earth and from man made activities.These experiments have answered many of the questions relatedto particle physics, astrophysics and even geophysics.India has a long tradition in neutrino physics. In fact, the firstever cosmic ray produced neutrino was detected in an experimentin the deep mines of Kolar Gold Fields in 1965. India is againplanning to setup an experiment called India-Based NeutrinoObservatory (INO) to study some of the properties of neutrinos.In this talk I will describe few of these experiments and theirfindings. I will also discuss the INO experiment and its physicspotential.
19-03-2013 At 04:00:00 PM
Speaker: Prof. Rahul Sinha , IMSc., Chennai
Category: TPSC HEP Seminar of General Interest
Venue: Lecture Hall
The Higgs boson is believed to have been discovered at the Large HadronCollider.The task now is to verify whether the boson is indeed the scalar Higgs asproposedin the Standard Model of particle physics, or something more esoteric asproposedin the plethora of extensions to the Standard Model. We present a step bystepmethodology to determine the properties of this resonance without makinganyassumptions about its couplings. We present the analysis in terms ofmeasurementsthat would require the minimum number of events. We show that by studyingthe threeuni-angular distributions and other readily measurable observables, one canunambiguouslyconfirm whether the new boson is indeed the Higgs with J^{PC} = 0^{++} andwith couplingsto Z bosons exactly as predicted in the Standard Model.
25-03-2013 At 04:00:00 PM
Speaker: Prof. D. P. Roy, HBCSE
Category: HEP Seminar
Venue: Lecture Hall
16-04-2013 At 04:00:00 PM
Speaker: Prof. Naresh Dadhich, Jamia Milia Islamia University
Category: TPSC HEP Seminar of General Interest
Venue: Lecture Hall
Subtleties of Einstein's gravity would be exposed, in particularhow gravitational self interaction is incorporated in Einstein's gravity?
17-04-2013 At 04:00:00 PM
Speaker: Mr. Suprabh Prakash, IIT, Bombay
Category: HEP Seminar
Venue: Lecture Hall
Various neutrino experiments till now, have explored the dominant 2-flavoreffects in neutrino oscillations.They have been very successful in constraining some of the oscillationparameters. The next step in thisfield is building experiments which will probe the sub-dominant 3-flavoreffects and the related oscillationparameters. This is a difficult task. In this talk, I will start with abrief discussion of the physics of neutrinooscillations. This will be followed by a discussion of the present statusof the neutrino oscillation parameters.Finally, I will present my work which is phenomenology of present and nextgeneration long baselinesuperbeam neutrino experiments.
18-04-2013 At 04:00:00 PM
Speaker: Dr. Gauhar Abbas (IMSc, Chennai)
Category: HEP Seminar
Venue: Lecture Hall
We determine the strong coupling constant alpha_s from the au; hadronic width using renormalization group summed expansion of the QCD Adlerfunction. The main theoretical uncertainty in the extraction of alpha_s is due tothe way in which renormalization group invariance is implemented and the yetuncalculated higher order terms in the QCD perturbative series. We show that new expansion exhibitsnice renormalization group improvement and the behaviour of the series is similar tostandard CIPT expansion. We further study the convergence properties of this expansion improved byBorel transformation and the analytical continuation in the Borel plane. We find that thenew, non-power expansions for different conformal mappings have remarkable convergence. Finally weprovide the value of strong coupling alpha_s using the new, non-power perturbative expansionswhich is alpha_s(M_ au ) = 0.3189+0.0145−0.0115, which translates to alpha_s(M_Z ) =0.1184+0.0018−0.0015.
19-04-2013 At 04:00:00 PM
Speaker: Sourabh Lahiri, KIAS (Seoul, S. Korea)
Category: CMP Seminar
Venue: Lecture Hall
06-05-2013 At 04:00:00 PM
Speaker: Prof. Prasanta Tripathy, IIT Chennai
Category: HEP Seminar
Venue: Lecture Hall
27-05-2013 At 04:00:00 PM
Speaker: Professor Sunanda Banerjee, SINP, Kolkata
Category: Colloquium
Venue: Lecture Hall
On July 4, 2012 two experiments, working at the CERN Large Hadron Collider, jointly announced a strong evidence of observing a new particle state. The observed particle, approximately 135 times heavier than proton and with a very short life time, could be the elusive Higgs boson which the high energy physicists have been earnestly looking for during the past 25 years. This will close one of the puzzles of the Standard Model of particle physics. More recent data have demonstrated some of the intrinsic properties of this new particle. The search involved a consolidated effort from thousands of physicists from all over the world over two decades. The challenges in this search and Indian effort in this process will be discussed.
31-05-2013 At 04:00:00 PM
Speaker: Dr. Tarun K. Jha, BITS, Pilani, Goa
Category: NP Seminar
Venue: Lecture Hall
05-06-2013 At 04:00:00 PM
Speaker: Prof. Hiranmaya Mishra, PRL, Ahmedabad
Category: HEP Seminar
Venue: Lecture Hall
The present talk will be based on kinetics of chiral transitions in quarkmatter that is probably produced resulting from a heavy ion collision.I will focus on far from equilibrium kinetics, subsequent to a quench froma dis ordered phase ( with zero quark condensates) to the ordered phase.This rapid quench renders the system thermodynamically unstable. Theevolution to the new equlibrium state is charecterized by spatio temporalpattern formation,with emergence and growth of domains of the preferred phase. Thisnonlinear evolution is usually referred to as phase ordering dynamics orcoarsening or domain growth.I will discuss the universal properties (e.g. growth laws, scaling ofcorrelation functions, bubble dynamics etc.) in the late stages of chiralkinetics.This will be presented within the Nambu-Jona Lasinio model to describechiral transition in strong interaction physics.
06-06-2013 At 11:30:00 AM
Speaker: Dr. Moumita Maiti, Department of Physics, Indian Institute of Technology Roorkee, Roorkee
Category: Dr. Aswini Kumar Rath Memorial Lecture
Venue: Lecture Hall
Use of radioisotopes or radiations has now been popular in different disciplines of sciences. Although nuclear reactor facilities have been the sole supplier of radioisotopes for a variety of applications, accessibly to the reactor is gradually decreasing. Alternatively, choice has been diversified from neutron rich to neutron deficient radionuclidesdue to the advancement in accelerator technology. However, production of neutron deficient radionuclides is not well explored in connection to their applications. My activities are mostly focused here. In this context, choice of radionuclide is an important issue where complete knowledge of nuclear and chemical data is mandatory. Nuclear reaction data helps to optimise the production parameters and chemical data an important helps to ensure the purity and quality of the product. Thus production of radioisotopes and preparation of radiotracers urges interdisciplinary research. In view of the growing demand, large number of nuclear and chemical data has been generated for the production of neutron deficient radionuclides which includes radioisotopes of terbium, gadolinium, astatine, technetium, ruthenium, zirconium, niobium, cadmium, thallium rhenium, etc. using our national accelerator facilities.Efficient chemical separation methods have been developed to separate the product from the corresponding bulk target. During my talk I shall discuss in detail our approach to address the subject.
12-06-2013 At 11:00:00 AM
Speaker: Prof. B.Rout, University of North Texas, Denton, Texas
Category: General Seminar
Venue: Lecture Hall
02-07-2013 At 04:00:00 PM
Speaker: Dr. Debajyoti Sarkar, City University, New York.
Category: HEP Seminar
Venue: Lecture Hall
23-07-2013 At 04:00:00 PM
Speaker: Dr. Pradipta Ghosh,Instituto de Fisica Teorica UAM/CSIC, Universidad Autonoma de Madrid
Category: HEP Seminar
Venue: Lecture Hall
The $mu$-from-$u$ supersymmetric standard model ($muu$SSM)offers a solution to the $mu$-problem and simultaneously accommodatemassive neutrinos through $R$-parity violation and a TeV scale seesawusing a set of right-handed neutrino superfields. In this model a verylightneutralino can still decay inside the LHC detector through an availableeven lighter scalar/pseudoscalar state, with light neutralino $ o$ lighterscalar/pseudoscalar + neutrino decay mode. We emphasize how thisunique feature can be utilized to study a non-standard Higgs signal at theLHC,with Higgs $ o$ a pair of light neutralino decay mode.We demonstrate how $muu$SSM can manifest itself through events withdisplaced multileptons at the LHC and provides unique signature for themodel.
25-07-2013 At 04:00:00 PM
Speaker: Professor Soumitra Sengupta, Indian Association of Cultivation of Sciences, Kolkata, India
Category: HEP Seminar of General Interest
Venue: Lecture Hall
Space and time, with their vastness and eternity, are thetwo integral parts for dynamical description of nature.But what are their true characters?This talk will be a non-technical review of the evolutionof concepts of space and time over the years from Newton to Einstein toHawking -- a journey of unveiling eternal mysteries.
26-07-2013 At 04:00:00 PM
Speaker: Dr. Natasha Sharma, USA Affiliation: University of Tennessee, Knoxville, Tennessee, USA.
Category: General Seminar
Venue: Lecture Hall
26-07-2013 At 11:00:00 AM
Speaker: Professor Soumitra Sengupta, Indian Association of Cultivation of Sciences, Kolkata, India
Category: HEP Seminar
Venue: Lecture Hall
Space-time with warped geometry plays important role in ourunderstanding of many phenomenology and cosmological scenario inbraneworld models. The Randall-Sundrum model in this context wasoriginally formualated on flat branes.In this work I shall try to address the possible origin of non-zerocosmological constant on the visible brane from bulk as well as branedynamics which may lead to an accelerating universe.
05-08-2013 At 04:00:00 PM
Speaker: Dr. Sarira Sahu, Institute of Nuclear Science National Autonomous University of Mexico, Mexico City
Category: General Seminar
Venue: Lecture Hall
12-08-2013 At 04:00:00 PM
Speaker: Professor K. Sridhar, Tata Institute of Fundamental Research, Mumbai
Category: Colloquium
Venue: Lecture Hall
I will present a review and status update of Non-Relativistic QCD (NRQCD)and its application to charmonium systems. In particular, I will bediscussing the production of charmonia at colliders and critically examinehow well NRQCD fares in describing the available data. To do this, I willbegin by presenting a historical account of the theoretical models thatwere developed to understand charmonium production and how these led to thedevelopment of the effective theory approach that we call NRQCD.
20-08-2013 At 04:00:00 PM
Speaker: Dr. Sinu Mathew, NUSNNI-NanoCore and Dept. of ECE, NUS Singapore
Category: Exp.Physics Seminar
Venue: Lecture Hall
The two-dimensional electron gas (2DEG) formed at the interface betweentwo band insulators LaAlO3 (LAO) and SrTiO3 (STO) is one of the mostfascinating systems in the field of oxide research. Tuning of theconductivity of this interface 2DEG and to create a spatially selectiveinsulating state is one of the key challenges in oxide electronics. Wefound that low Z ion irradiation can be utilized to manipulate theconductivity at the LAO/STO interface by carrier localization arising fromthe defects created by the ion beam exposure, and eventually producing aninsulating ground state. The results of electrical transport, Ramanspectroscopy and spectroscopic ellipsometry will be discussed. This processof ion induced defect creation results in structural changes in SrTiO3 asrevealed by the appearance of symmetry forbidden first-order TO2, andTO4 vibrationalmodes in the Raman spectra of the irradiated samples. In spectroscopicellipsometry measurements, the optical conductivity features of theirradiated interface were found to be broadened due to the localizationeffects along with a decrease of spectral weight from 4.2-5.4 eV. Theseresults indicate that the interface ground state (metallic/insulating) atthe LAO/STO can be controlled by engineering the SrTiO3 with ionirradiation. The consequences of the irradiation effects and possibleorigin of the reduction in conductivity will be discussed.
23-08-2013 At 04:00:00 PM
Speaker: Prof. A.M. Srivastava, IOP, Bhubaneswar
Category: General Seminar
Venue: Lecture Hall
26-08-2013 At 04:00:00 PM
Speaker: Dr. A. Rath, Post Doctoral Fellow, I I Sc., Bangalore
Category: Experimental Condensed Matter Seminar
Venue: Lecture Hall
In nano particle, length of the atomic column varies from centerof the grain to the edge which resulted in curved lattice planes (off zoneaxis tilting) and delocalization (can be solved using Cs correctedmicroscope). Overlap of the top atomic column with bottom of an adjacentcolumn give rise to fringe pattern having deceptive lattice spacing. Inthis talk, we will discuss the various reasons for the deceptive latticespacing in HRTEM imaging and its rectification.This technique will help usin analyzing the strain and composition of bimetallic nanoparticles withmore accuracy. In addition to this, we will discuss about the Precessionelectron Diffraction technique(PED) which is an advanced TEM technique foranalyzing the strain in bulk and thin film samples.
02-09-2013 At 07:00:00 PM
Speaker: Ar. Shakti Nanda, BBSR
Category: Evening Colloquium
Venue: Lecture Hall
02-09-2013 At 11:00:00 AM
Speaker: Prof. Sreerup Raychaudhuri,, TIFR, Mumbai
Category: HEP Seminar
Venue: Lecture Hall
The present status of supersymmetric models in the aftermath of the Higgs boson discovery will be discussed. Prospects for discovery of supersymmetry at future colliders and possible probes of the decoupling limit will also be described. Somealternatives to supersymmetry will be briefly touched upon.
09-09-2013 At 11:00:00 AM
Speaker: Dr. Priti Sundar Mohanty (Lund University, Sweden)
Category: CMP Seminar
Venue: Lecture Hall
19-09-2013 At 04:00:00 PM
Speaker: Prof.C.S. Shastry, Adjunct Professor, Amrita University, Coimbatore
Category: General Seminar
Venue: Lecture Hall
24-09-2013 At 04:00:00 PM
Speaker: Prof. Chandrabhas Narayan, JNCASR, Benguluru
Category: General Seminar
Venue: Lecture Hall
Raman Spectroscopy has been used in various areas post its discovery in1928. In the past decade, the potential of Raman Spectroscopy to be used inBiology has been increasingly appreciated. The ease of performing Ramanspectroscopy and the miniaturization of the spectrometer, has made it anattractive point of care diagnostic tool. In this talk I would like todemonstrate the two applications of Raman spectroscopy, namely, non-PCRbased bio-diagnostic application and potential of Raman as a per-screeningtool for drug discovery.
25-09-2013 At 12:00:00 PM
Speaker: Dr. Padmanabhan Balasubramanian, PDF, IOP
Category: Experimental CMP Seminar
Venue: Lecture Hall
27-09-2013 At 04:00:00 PM
Speaker: Dr. Sidharat Kumar Prasad, Bose Institute, Kolkata
Category: General Seminar
Venue: Lecture Hall
Observations of large elliptic flow and suppressed particle production atthe Relativistic Heavy Ion Collider (RHIC) at Brookhaven National Laboratory (USA) have provided strong evidence, that a de-con ned phase of matterconsisting of quarks and gluons commonly known as the Quark Gluon Plasma(QGP) is produced in very high energy nucleus-nucleus collisions. The pro-duction of the QGP is now further explored at the Large Hadron Collider(LHC) at CERN which produces Pb on Pb collisions at 2.76 TeV.At this unprecedented large collision energy, large momentum transferprocesses' cross sections are signi cantly enhanced. It has thus become pos-sible to carry out detailed and robust measurements of jet medium inter-actions. I will present a summary of key results obtained by the ALICEcollaboration in measurements of ow and jet production. My main focuswill be on measurements of charged particle jet production cross sections andjet shapes in proton-proton collisions at 7 TeV. Measured jet production crosssection, charged particle multiplicity in the leading jet, transverse momen-tum distribution about the jet axis, and jet size are compared to predictionsfrom various Monte Carlo models.
27-09-2013 At 11:30:00 AM
Speaker: Dr. T. L. Underwood, University of Edinburgh,UK
Category: Experimental CMP Seminar
Venue: Lecture Hall
Alloys are mixtures of two or more metals. Alloys in which the positionsof the atoms form an approximate crystal structure, but where the patternformed by considering the chemical elements to which the atoms belong isnot periodic, are of fundamental importance to metallurgy andnanotechnology. Atoms belonging to the same element in such 'disorderedalloys' will exhibit a variety of environments. For example, in an alloyconsisting of two elements A and B, the environment of an A atom couldconsist entirely of A atoms, entirely of B atoms, or a mixture of both.Differences in the environments of A atoms leads to differences in theelectronic structures 'within' these atoms, which can be detectedexperimentally using core-level X-ray photoelectron spectroscopy(CL-XPS). Therefore the prospect exists of using CL-XPS to probe specificatomic environments in alloys. One possible application of this is tonon-destructively characterise alloy-based nanomaterials and nanodeviceson the atomic scale. However, to make this a reality one must understandthe relationship between an atom's environment, its electronic structure,and the binding energies of its core levels. I will describe a simple model for the distribution of core level bindingenergies in alloys, and apply it to a variety of disordered alloys, withthe aim of elucidating the relationship between atomic environment andcore level binding energies in alloys. The model reveals a number ofinteresting phenomena which must be taken into account when interpretingthe CL-XPS spectra of these systems. These include anomalously large'disorder broadenings' of spectra in alloys exhibiting inhomogeneousconcentration profiles; and a counterintuitive relationship between anatom's core level binding energies, and its local and globalconcentration of 'unlike' atoms: increasing the local concentrationalters the core level binding energies in the opposite direction toincreasing the global concentration.
09-10-2013 At 04:00:00 PM
Speaker: Dr. Debakanta Samal, Institute for Nanotechnology, University of Twente, Netherland
Category: General Seminar
Venue: Lecture Hall
The last decade has witnessed explosive growth of research on various oxide heterostructures, resulting in the discovery of exciting interfacial phenomena. However, it remains elusive hitherto to control and subsequently measure oxygen sub-lattice in oxide thin films/heterostructures that plays a pivotal role in the structure-property affairs. Specifically, the crystallographic mismatch, violation of local charge neutrality and the difference in chemical potentials between the constituents belonging to thin films/heterostrutures, strongly modify the atomic/electronic structure by - (i) electronic and/or atomic reconstruction (ii) formation of oxygen and/or cation vacancies as well as (iii) large atomic displacements. In this talk, I will present our recent results on ultrathin cuprate layers that undergo profound change in the oxygen sub-lattice structure giving rise to novel structural and electronic properties. In the first half, I will discuss about the infinite-layer SrCuO2, which in the bulk-form, has each Cu2+ ion coordinated by four planar O2- ions. However, for ultrathin layers, we find atransformation from bulk-planar to chain-type structure having apical oxygen via atomic rearrangement [1,2]. This phenomena turns out to be a direct consequence of electrostatic instability associated with the polar nature of SrCuO2. We illustrate that the geometry of CuO4 plaquette in polar cuprates can precisely be controlled from in-plane to out-of-plane upon reducing the film thickness at the sub-unit cell level and this opens possibilities to design structures that have specific functions, e.g. current-carrying layers, charge reservoirs and scaffolding layers. In the second half, I will discuss about CuO, which unlike other 3d transition metal monoxides is found in a low symmetry distorted monoclinic structure rather than rocksalt structure. We demonstrate direct evidence of strain-induced structural transformation from monoclinic to tetragonal phase for ultrathin CuO films grown on SrTiO3 [3]. The experimental confirmation of the high symmetry structure of CuO opens up new avenues to explore electronic and magnetic properties in the context of high Tcsuperconductivity.References:1. D. Samal, G. Koster, et al., Phys. Rev. Lett., 111, 096102 (2013)2. B. Kuiper, D. Samal, G. Koster, et al., Control of oxygen sub-lattice structure in ultrathinSrCuO2 films studied by X-ray photoelectron diffraction (APL materials, 2013 in press)3. D. Samal, G. Koster, et al., Direct structural and spectroscopic investigation of ultrathinfilms of tetragonal CuO: Six-fold co-ordinated copper (Under review)
10-10-2013 At 04:00:00 PM
Speaker: Dr. Rishi Khatri, Max-Planck-Institut für Astrophysik, Germany
Category: HEP talk of General Interest
Venue: Lecture Hall
With the success of Planck experiment we have extracted almost all information in the primary temperature anisotropies of CMB. Since Silk damping erases almost all primary perturbations on scales smaller than the Planck/SPT/ACT resolution, it is not possible to make significant progress by further improvement in resolution and we must look elsewhere as far as the initial conditions of the Universe are concerned. The informationerased by Silk damping from the anisotropies ends up as spectral deviations from a blackbody in the CMB spectrum. CMB spectral deviations (mu-type and i-type) can thus gives us new information about the primordial power spectrum on very small scales (ell ~ 10^5-10^8, corresponding to conventional anisotropy experiment with angular resolution of 6 milli-arcsec) which cannot be measured directly. In terms of inflation or initial conditions, these measurements will increase our view of inflation from 7 e-folds accessible at present from the observations of CMB anisotropies and large-scale structure to more than 17 e-folds. I will briefly review the physics behind the spectral features and discuss what information can be gained from their measurement with experiments such as Pixie and PRISM.
17-10-2013 At 04:00:00 PM
Speaker: Dr. Suvankar Chakraverty, Riken Center for Emergent Matter Science, Japan
Category: General Seminar
Venue: Lecture Hall
Oxide thin films and interfaces have attracted considerable interestnot only because of the rich physics it can host but also because ofthe possibility of integrating materials with different properties toachieve new multifunctionality that can be used for future generationof high speed, low power consuming and small size spintronics devices.Recently discovered topologically protected non-trivial magnetic spinstructures namely “skyrmions†have shown their potential for low powerconsuming, small size and high speed spintronics devices. So far,formation of skyrmionic crystals have been observed in chiralnoncentrosymmetric B20-type compounds mediated by the Dzyaloshinskii-Moriya (D-M)interaction. On the other hand, in centrosymmetriccrystals without D-M interaction, such nontrivial spin structure hasbeen proposed to occur, yet compelling evidence has remained to bepresented. We have shown the emergence of such non-trivial spintexture in centrosymmetric simple cubic perovskite SrFeO3 thin filmsthrough the combine methods of topological hall effect andresonant soft x-ray diffraction measurements. On the other hand, wehave observed that isoelectronic BaFeO3 is an unusual ferromagneticinsulator. A systematic doping of Sr in Ba - site give rise toinsulator-metal to ferromagnetic-skyrmionic transition, throughpossible skyrmionic-insulating phase. Using controlledSr0.5Ba0.5FeO3-La0.7Sr0.3MnO3 interface we have shown the possibility ofinducing non-trivial spin structure in ferromagnetic La0.7Sr0.3MnO3 layer,that has been detected by the topological transport through thatinterface. In this presentation I will talk about:1. A unique example of magnetic skyrmionic crystal formation in acentrosymmetric perovskite oxide and its detection through“Topological Hall Effect (THE)â€.2. BaFeO3 to SrFeO3 : Ferromagnetic insulator to skyrmionic metaltransition.3. Topological transport at Sr0.5Ba0.5FeO3-La0.7Sr0.3MnO3 interface.Double perovskite oxide film and interface.
17-10-2013 At 02:45:00 PM
Speaker: Dr. Sudipta Muhuri, University of Pune, Pune
Category: Group Seminar
Venue: Lecture Hall
We analyze the dynamics of overlapping antiparallel treadmillingmicrotubules in the presence of crosslinking processive motor proteinsthat counterbalance an external force. We show that coupling the force-dependent velocity of motors and the kinetics of motor exchange with abath in the presence of treadmilling leads generically to oscillatorybehavior. In addition, we show that coupling the polymerization kineticsto the external force through the kinetics of the crosslinking motors canstabilize the oscillatory instability into finite-amplitude nonlinearoscillations and may lead to other scenarios, including bistability. Reference : (2012) EPL 98 68005
18-10-2013 At 04:00:00 PM
Speaker: Prof. Hans Hofsäss, University Göttingen, Germany
Category: Colloquium
Venue: Lecture Hall
In this lecture I first discuss the fundamentals of self-organizedformation of nanoscale dot and ripple patterns due to ion-inducedperturbation of a surface layer which exhibits a certain ion-inducedviscosity. Viscous flow is the smoothing mechanism and ion-inducederosion and subsurface mass transport in the collision cascade is theroughening mechanism.Examples of ripple pattern formation on Si, SiO_2 and a-C surfaces anddifferent incident ions are presented. The experimental observations arethen compared to predictions made by simple theoretical models. Theparameters needed in the theoretical models are obtained from binarycollision Monte Carlo Simulations (SDTRIM) or molecular dynamicssimulation. In this context the crater function concept is exemplified.The important role of metal impurities on pattern formation ishighlighted with several examples. It is shown that silicide or carbideformation is now the driving force for pattern formation. Co-depositionof metal impurities from multiply sources allow the design of dotpatterns with predefined symmetry.Finally I discuss the dynamic behavior of ion induced patterns, inparticular the propagation of ripples across the surface. Recentexperiments on ripple propagation will be compared with theoreticalpredictions with some surprising results.
23-10-2013 At 04:00:00 PM
Speaker: Prof. Pushpa Khare, IUCAA, Pune
Category: TPSC Seminar of General Interest
Venue: Lecture Hall
24-10-2013 At 04:00:00 PM
Speaker: Prof. Avinash Khare, IISER, Pune
Category: General Seminar
Venue: Lecture Hall
25-10-2013 At 04:00:00 PM
Speaker: Dr. Rabinarayan Mishra, Ravenshaw University, Cuttack
Category: General Seminar
Venue: Lecture Hall
04-11-2013 At 04:00:00 PM
Speaker: Dr. Shankha Deep Chakrabortty, IMSc., Chennai
Category: HEP Seminar
Venue: Lecture Hall
04-11-2013 At 11:00:00 AM
Speaker: Dr. Biswajit Ransingh, NIT, Rourkela
Category: HEP Seminar
Venue: Lecture Hall
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11-11-2013 At 04:00:00 PM
Speaker: Dr. Sarbani Majumdar, Bose Institute, Kolkata
Category: HEP Seminar
Venue: Lecture Hall
11-11-2013 At 11:30:00 AM
Speaker: Prof. Soma Sanyal,Physics Department, Hyderabad University.
Category: TPSC Seminar of General Interest
Venue: Lecture Hall
12-11-2013 At 04:00:00 PM
Speaker: Dr. Sasmita Mishra, PRL, Ahmedabad
Category: HEP Seminar
Venue: Lecture Hall
13-11-2013 At 04:00:00 PM
Speaker: Dr. Vivek Vyas , IISER, Kolkata
Category: HEP Seminar
Venue: Lecture Hall
19-11-2013 At 04:00:00 PM
Speaker: Dr. Somnath De, VECC, Kalkata
Category: HEP Seminar
Venue: Lecture Hall
20-11-2013 At 04:00:00 PM
Speaker: Dr. D.P. Datta, PDF,IOP, Bhubaneswar
Category: General Seminar
Venue: Lecture Hall
A porous layer containing interconnecting network of nanofibersis known to be formed in GaSb under irradiation of ion beamshaving energy varying from tens of keV to a few MeV. Earlierstudies on such structural modifications of GaSb were focusedon the low fluence range (up to ~1??10^16 ions cm^-2). Theevolution of nanofibrous layer in the high fluence regime hasremained unexplored although in addition to understanding themicrostrcutural development, this regime is also important inthe context of self-organized surface patterning under irradiation.In the present study we show that normally and obliquely incident(theta = 60^0) 60 keV Ar^+ -ion irradiation of GaSb in the fluencerange 7??10^16 -3??10^18 ions cm^-2 demonstrates hitherto unobservedstructural modifications. In particular, we find obliquely incidentirradiation induced formation and gradual embedding of thenanofibrous layer under a rough top surface. In addition, theirradiation results in simultaneous formation of an undulatinginterface of the nanofibrous layer with the underlying GaSbcrystalline substrate. The observed structural evolution isunderstood in terms of redeposition of sputtered atoms-from Ar-ionbombarded GaSb-onto the nanofibrous layer growing byaccumulation of ion induced vacancies. We further address theissues of the crystallinity and compositional modifications of thenanofibrous layer under such high fluence irradiation. Finally,as further exploration of high fluence induced evolution of ananofibrous layer, we present the structural modification in InSbunder similar experimental conditions, namely, under normally andoff-normally (theta = 60^0) incident 60 keV Ar^+ -ion bombardmentin the fluence range of 1??10^17 - 3??10^18 ions cm^-2.
27-11-2013 At 04:00:00 PM
Speaker: Dr. Biplob Bhattacherjee, Kavli IPMU, University of Tokyo, Japan
Category: HEP Seminar
Venue: Lecture Hall
The main focus of my talk would be on supersymmetry search in the contextof recent LHC results. The discovery of 125 GeV Higgs like boson constrainssupersymmetry in many different directions. I will discuss a few viablesupersymmetric models and challenges involved in the search prospect. AlsoI would briefly highlight the importance of dark matter searches in a moregeneral framework.
02-12-2013 At 04:00:00 PM
Speaker: Dr. Vipin K. Yadav, Planetary Science Branch (PSB) , Space Physics Laboratory (SPL) , Vikram Sarabha
Category: Colloquium
Venue: Lecture Hall
Mars, named after the Roman god of war, is the fourth planet from theSun in our solar system. After moon, Mars is second most fascinating and soughtafter astronomical object for the humans on as it can also be seen from the Earthwith naked eyes. The conditions in Mars are believed to be hospitable since theplanet is similar to earth in many ways. Mars can prove to be a very good laboratoryto study a typical planet environment where one can study Mars' surface,gravitational and magnetic fields. Mars Orbiter Mission (MOM) is India?€?s firstinterplanetary mission to planet Mars with an orbiter craft designed to orbit marsin an elliptical orbit of 376 km to 80,000 km. It is ISRO?€?s second space launchafter the success of Chandrayaan-1 in October 2008. The MOM spacecraft weigh 1337 kgand has been configured to carry out observations with five scientific instrumentsnamely Mars Color Camera (MCC), Methane Sensor for Mars (MSM), Thermal infra-redImaging Spec! trometer (TIS), Lyman Alpha Photometer (LAP) and Mars Exospheric NeutralComposition Analyzer (MENCA) onboard to explore various facets of planet Mars. Allthese five payloads are designed and developed indigenously ?€? MCC, MSM and TIS bySpace Application Centre (SAC) Ahmedabad, LAP by Laboratory for Electro-OpticalSystems (LEOS) Bangalore and MENCA by Space Physics Laboratory (SPL) at VikramSarabhai Space Centre (VSSC). MOM was launched with PSLV-XL (C-25), a variant ofISRO?€?s most reliable workhorse PSLV on November 5, 2013 afternoon. One of themain objectives of MOM is to develop the space transportation technologies requiredfor design, planning, management and operations of an interplanetary mission. Thescientific objective is the exploration of Mars surface features, morphology,topography, mineralogy and Martian atmosphere by indigenous scientific instruments.
02-12-2013 At 11:00:00 AM
Speaker: Dr. Subroto Mukherjee, Head, FCIPT, IPR, Gandhinagar
Category: General Seminar
Venue: Lecture Hall
Plasma the fourth state of matter comprising of ions, electronsand neutrals can be used for surface engineering of materials, therebyincreasing their life. The modifications can be below or above thesurface. Most of these technologies are environment friendly and do notemit any pollutants. At FCIPT a lot of such technologies are developed andtransferred to industries. The presentation will focus on use of suchtechniques for solar applications.
09-12-2013 At 04:00:00 PM
Speaker: Dr. Dibakar Raychowdhury, IISER, Bhopal
Category: HEP Seminar
Venue: Lecture Hall
10-12-2013 At 04:00:00 PM
Speaker: Dr. Ayan Mukhopadhyay, Postdoctoral Researcher, CPHT Ecole Polytechnique and IPHT CEA-Saclay
Category: Colloquium
Venue: Lecture Hall
10-12-2013 At 04:00:00 PM
Speaker: Dr. Ayan Mukhopadhyay, Postdoctoral Researcher, CPHT Ecole Polytechnique and IPHT CEA-Saclay
Category: HEP Seminar
Venue: Lecture Hall
11-12-2013 At 04:00:00 PM
Speaker: Dr. Sanjit Das ,IIMs, Chennai
Category: HEP Seminar
Venue: Lecture Hall
11-12-2013 At 11:00:00 AM
Speaker: Dr. Ayan Mukhopadhyay, Postdoctoral Researcher, CPHT Ecole Polytechnique and IPHT CEA-Saclay
Category: HEP Seminar
Venue: Lecture Hall
13-12-2013 At 04:00:00 PM
Speaker: Prof. Dipankar Banerjee , Indian Institute of Astrophysics, Bangalore
Category: Seminar of General Interest
Venue: Lecture Hall
16-12-2013 At 04:00:00 PM
Speaker: Dr.A.K.Sarangi , UCIL
Category: Seminar of General Interest
Venue: Lecture Hall
16-12-2013 At 11:00:00 AM
Speaker: Dr. Gaurav Narian ,IMSc., Chennai
Category: HEP Seminar
Venue: Lecture Hall
23-12-2013 At 04:00:00 PM
Speaker: Dr. Manimala Mitra , IPPP, Durham
Category: HEP Seminar
Venue: Lecture Hall
24-12-2013 At 04:00:00 PM
Speaker: Dr. Kenji Nishiwaki , HRI, Allahabad
Category: HEP Seminar
Venue: Lecture Hall
24-12-2013 At 11:00:00 AM
Speaker: Dr. Areejit Samal , ICTP, Trieste, Italy
Category: CMP Seminar
Venue: Lecture Hall
30-12-2013 At 04:00:00 PM
Speaker: Dr. Poulomi Sadhukhan , University of Gottingen, Germany
Category: Condensed Matter Theory Seminar
Venue: Lecture Hall