http://hdl.handle.net/2289/22 Search the Channel search http://dspace.rri.res.in:8080/jspui/simple-search http://hdl.handle.net/2289/4226 Title: Work fluctions for a harmonic oscillator driven by an external random force<br/><br/>Authors: Sabhapandit, Sanjib<br/><br/>Abstract: The fluctuations of the work done by an external Gaussian random force on a harmonicoscillator that is also in contact with a thermal bath are studied. We have obtained the exact largedeviation function as well as the complete asymptotic forms of the probability density function.The distribution of the work done is found to be non-Gaussian. The steady-state fluctuationtheorem holds only if the ratio of the variances, of the external random forcing and the thermalnoise, respectively, is less than 1/3. On the other hand, the transient fluctuation theorem holds(asymptotically) for all the values of that ratio. The theoretical asymptotic forms of the probabilitydensity function are in very good agreement with the numerics as well as with an experiment.<br/><br/>Description: Restricted Access. http://hdl.handle.net/2289/4220 Title: Robustness of non-gaussian entanglement against noisy amplifier and attenuator environments<br/><br/>Authors: Sabapathy, Krishna Kumar; Ivan, J Solomon; Simon, R.<br/><br/>Abstract: The recently developed Kraus representation for bosonic Gaussian channels is employed to study analytically the robustness of non-Gaussian entanglement against evolution under noisy attenuator and amplifier environments, and compare it with the robustness of Gaussian entanglement. Our results show that some non-Gaussian states with one ebit of entanglement are more robust than all Gaussian states, even the ones with arbitrarily large entanglement, a conclusion of direct consequence to the recent conjecture by Allegra et al. [Phys. Rev. Lett. 105, 100503 (2010)PRLTAO0031-900710.1103/PhysRevLett.105.100503].<br/><br/>Description: Open access http://hdl.handle.net/2289/4207 Title: Tunable thermal conductivity in defect engineered nanowires at low temperatures<br/><br/>Authors: Dhara, Sajal; Solanki, Hari S.; Pawan R, Arvind; Singh, Vibhor; Sengupta, Shamashis; Chalke, B. A.; Dhar, Abhishek; Gokhale, Mahesh; Bhattacharya, A.; Deshmukh, Mandar M.<br/><br/>Abstract: We measure the thermal conductivity (κ) of individual InAs nanowires (NWs), and find that it is three orders of magnitude smaller than the bulk value in the temperature range of 10–50 K. We argue that the low κ arises from the scattering of phonons in the random superlattice of twin defects oriented perpendicular to the axis of the NW. We observe a significant electronic contribution arising from the surface accumulation layer, which gives rise to the tunability of κ with the application of an electrostatic gate and a magnetic field. Our devices and measurements of κ at different carrier concentrations and magnetic field offer a means to study unique aspects of nanoscale thermal transport.<br/><br/>Description: Open Access http://hdl.handle.net/2289/4169 Title: Gravitational waveforms for binary black holes<br/><br/>Authors: Iyer, B.R.<br/><br/>Abstract: Over the last decade gravitational waveforms of binary black holes have been investigated using a variety of approaches like the Multipolar post-Minkowskian formalism, Numerical Relativity and the Effective-One-Body method. We review these complementary approaches and summarize the current status of these investigations of relevance to construct the best templates for the next generation Advanced gravitational wave detectors.<br/><br/>Description: Restricted Access