Department of Physics In-House Symposium 2008
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DEPARTMENT OF PHYSICS IN-HOUSE SYMPOSIUM 2008 INDIAN INSTITUTE OF SCIENCE BANGALORE 560012 (NOVEMBER 24-25, 2008) FORWARD As a periodic review of its activities, The Department of Physics has been organizing In-House Symposium on annual basis during recent years. This one-day symposium usually consists of oral presentations by selected faculty members and students, and poster presentations by all those who would like to present their recent results. This year we have 10 talks by faculty, 2 by post-doctoral fellows, 17 by the senior students and as many as 28 posters by the rest. I hope this package would be as reasonable representation of the ongoing research activities in the department. This event is also particularly useful to freshers to familiarize themselves with the current research activity in our Department in various branches of Physics. I would like to thank Drs. Prabal Maiti, Arindam Ghosh and Banibrata Mukhopadhyay of our Department who have shouldered the responsibility to organize this In-House Symposium. I urge all of you to actively participate in this important scientific activity. I hope you will all have an enjoyable and fruitful day. Prof. Chandan Dasgupta Chairman November 24-25, 2008 IN-HOUSE SYMPOSIUM DEPARTMENT OF PHYSICS Indian Institute of Science November 24-25, 2008 TECHNICAL PROGRAMME (Venue: Physics Lecture Hall- I) Day 1 (24/11/2008) 08.55-09:00 Welcome Chandan Dasgupta 09:00-10:25 SESSION I Chair: Vasant Natarajan 09:00-09:20 F1 Chanda J. Jog The surprisingly flattened dark matter halo of the Andromeda Galaxy 09:20-09:40 F2 H. R. Krishnamurthy Novel Physics in Hetero-structures of Strongly Correlated Materials 09:40-09:55 S1 S. Srivastava Polymer nanocomposites near glass transition: Role of interface 09:55-10:10 S2 Naresh Babu Pendya Observation of low temperature Persistent Photoconductivity in flower shaped dendritic PbS structures 10:10-10:25 S3 T. Phanindra Sai Fabrication and Electrical Characterization of Charge Transfer Molecular Wires 10:25-11:00 TEA 11:00-12:55 SESSION II Chair: Prabal K Maiti 11:00-11:20 F3 Chandan Dasgupta Growing length and time scales in glass forming liquids 11:20-11:40 F4 Jaydeep Basu Nanophotonics with Quantum Dot Arrays and Optical Near Fields 11:40-11:55 S4 S. K. Biswas Diffuse optical tomographic non-invasive breast and brain imager using a single laser light source 11:55-12:10 S5 Murthy O. V. S. N High pulsed field magnetotransport and hole mobility in HgCdTe 12:10-12:25 S6 K. G Padmalekha EMR Studies of LSMO nanoparticles dispersed in PVA 12:25-12:40 S7 Mogurampelly Santosh Force Induced DNA Melting 12:40-12:55 S8 N. Kamaraju Ultrafast electron dynamics and cubic optical nonlinearity of single and double walled carbon nanotubes 12:55-14:00 LUNCH 14:00-15:30 POSTER + TEA 15:30-17:15 SESSION III Chair: Rahul Pandit 15:30-15:50 F5 A. K. Sood Nonequilibrium Fluctuations in Sheared Jammed States 15:50-16:10 F6 K. P. Sinha Extended Einstein-Hilbert (E-H) action and the emergence of Riccions as cosmic dark matter and consequent cosmic acceleration 16:10-16:25 S9 Sunil Kumar Low frequency vibrational modes in carbon nanotubes: terahertz time domain spectroscopy 16:25-16:45 P1 Rema Krishnaswamy Jamming and shear banding in two dimensional suspensions 16:45-17:00 S10 Surajit Saha Phonon anomaly in pyrochlore spin-ice Dy2Ti2O7 and non- magnetic Lu2Ti2O7: A temperature dependent Raman and x-ray study 17:00-17:15 S11 K Vijay Kumar Brownian Inchworm Model of a Self-propelled particle Day 2 (25/11/2008) 09:00-10:25 SESSION IV Chair: V. Venkataraman 09:00-09:20 F7 Ramesh Chandra Mallik Thermoelectric Properties of Co4Sb12 Skutterudite Materials with In Addition 09:20-09:40 F8 Diptiman Sen Scattering of electrons from an interacting region 09:40-09:55 S12 Prasad Perlekar Statistically Steady Turbulence in Soap Films: Direct Numerical Simulations with Ekman Friction 09:55-10:10 S13 Samriddhi Sankar Ray Hyperviscosity, Bottlenecks and New Surprises in the Galerkin- truncated Burgers Equation 10:10-10:25 S14 Avatar Tulsi General framework for quantum search algorithms 10:25-11:00 TEA 11:00-12:40 SESSION V Chair: S. V. Bhat 11:00-11:20 F9 S. Ramakumar Crystal Structures of native and substrate complex of an alkali thermostable xylanase from an alkalophilic Bacillus sp. NG-27. Structural insights into alkalophilicity. 11:20-11:40 F10 Arindam Ghosh Intrinsic magnetism in high-mobility semiconductor – a bottom-up route to spin-electronics? 11:40-11:55 S15 D. Samal The incongruous observation of phase separation in La0.85 Sr0.15CoO3 spin –glass system 11:55-12:10 S16 Amrita Singh New electrochemistry based route to Materials Engineering in Nanoscale Systems 12:10-12:25 S17 M Suheshkumar Singh Ultrasound-modulated Diffuse Optical Tomographic Imaging System for Screening Breast Cancer 12:25-12:45 P2 Norio Kikuchi A filament in an active medium: buckling, stiffening and negative dissipation VOTE OF THANKS BY CHAIRMAN POSTERS No Name Title P1 Arjun Joshua and V. Venkataraman Enhancement of sensitivity of detection of Kerr rotation by time averaging P2 Vikram Rathee, Sajal Kumar Ghosh, Rema Krishnaswamy, V. A. Raghunathan and A. K. Sood Reentrant phase behavior of a mixed surfactant system with strongly binding counter-ions P3 Geetanjali, D. Banerjee and S V Bhat Structural, magnetic and EMR studies of CaMnO3 nanoparticles P4 Sayak Ghoshal and P.S.Anil Kumar Magnetic and Magnetotransport studies of ZnO films with and without intrinsic magnetic moment P5 Sumilan Banerjee, Chandan Dasgupta, and T. V. Ramakrishnan Ginzburg Landau Theory for Cuprate Superconductivity P6 Suropriya Saha and Sriram Ramaswamy Non Equilibrium noise in electrophoresis: the micro-ion wind P7 Sakshath. S. and P. S. Anil Kumar Magnetic Anisotropy in Epitaxial Fe/MgO films grown by Pulsed Laser Deposition P8 Debangsu Roy, and P.S. Anil Kumar Observation of the exchange spring behavior in hard-soft- ferrite nanocomposite P9 Biswanath Chakraborty, Anindya Das and A.K. Sood Probing the local stress in Graphene by Raman Spectroscopy P10 Chinkhanlun Guite and V. Venkataraman Electrical detection of spin polarized electrons in semiconductors using a radio- frequency pick-up coil P11 Anupam Gupta, Prasad Perlekar, and Rahul Pandit Polymer Addtives in Decaying Two-Dimensional Turbulence P12 Smarajit Karmakar, Chandan Dasgupta and Srikanth Sastry Numerical study of a glass forming liquid in two dimensions to test the dimension dependence of the Adam-Gibbs relation P13 Ramakanta Naik,R.Ganesan,K.S.Sangunni. Compositional dependence of the optical changes in (As2S3)1-xSbx chalcogenide film. P14 Nitin P. Lobo and K.V. Ramanathan Measurement of Heteronuclear dipolar couplings- A systematic study of cross polarization dynamics for Separated Local Field (SLF) experiments P15 S.M. Mohanasundaram and Arindam Ghosh Detection of microcantilever deflection using electron transport measurements P16 Chandni U and Arindam Ghosh A fluctuation-based probe to criticality in structural transitions P17 Jayakrishna Khatei and K.S.R. Koteswara Rao Temperature dependent photoluminescence study in Hg1-xCdxTe (x~0.8) nano and microcrystals P18 Alok Ranjan Nayak, T.K. Shajahan, and Rahul Pandit The Dependance of Spiral-Wave Dynamics on Inhomogeneities in the TNNP Model of Cardiac Tissue P19 Nitin Kumar, Sayantan Majumdar, Aditya Sood, Rama Govindarajan, Sriram Ramaswamy and A.K. Sood Motion of falling spheres and rising bubbles in a viscoelastic gel: spontaneous oscillations and bursting P20 Sayantan Majumdar and A.K. Sood Negative viscosity fluctuations and their universality in a driven repulsive colloidal glass P21 Aditya A. Wagh, H.L.Bhat, P. S. Anil Kumar and Suja Elizabeth MAGNETOTRANSPORT STUDIES OF FLOAT ZONE-GROWN Gd1- xSrxMnO3 SINGLE CRYSTAL P22 Paramita Kar Choudhury, Debjani Bagchi, and Reghu Menon Conformational modification by conjugation length and solvent in rigid-rod organic semiconductor P23 K Jugeshwar Singh, G Clark, K P Ramesh and Reghu Menon H-NMR and charge transport in metallic polypyrrole at ultra-low temperatures and high magnetic fields P24 Atindra Nath Pal and Arindam Ghosh Resistance noise in electrically biased bilayer graphene P25 Meghana Dharmik and Prabal Maiti Structure and stability of carbon and boronnitride nanorings P26 R.Koushik and Arindam Ghosh Conductivity noise in strongly correlated systems P27 Manas Khan and A. K. Sood Out-of-Equilibrium Microrheology to Probe Directional Viscoelastic Properties under Shear P28 Biswaroop Mukherjee, Prabal K. Maiti, Chandan Dasgupta and A. K. Sood Jump reorientation of water molecules confined in narrow carbon nanotubes TALK ABSTRACTS The surprisingly flattened dark matter halo of the Andromeda Galaxy Chanda J. Jog The rotation curve of a spiral galaxy is normally used to deduce its dark matter halo content. Another complementary constraint is provided by the vertical scale- heights of the interstellar gas, but this has not been exploited much in the literature. We use both these for the nearby Andromeda galaxy to determine its halo density distribution (Banerjee & Jog 2008, Astrophysical Journal, 685, 254). We model the galaxy as a gravitationally coupled star-gas system responding to the external force-field of the dark matter halo. We show that a highly flattened oblate halo with an axis ratio of 0.4, and an isothermal density profile, provides the best fit to the observed data. The flattened shape of the dark matter halo is a robust result, and is strikingly different from the spherical shape generally assumed. This has important implications for galaxy formation which will be discussed. A similar approach has been applied to the low surface brightness galaxy UGC 7321 for which the scaleheight information is available. Here the best-fit result from our model implies high gas dispersion, this could explain the low star formation seen in this galaxy (Banerjee, Matthews & Jog 2008, Mon.