Showing papers by "Bidhan Chandra Bag published in 2004"
TL;DR: This work extends the treatment to explore several systematic approximation schemes for the solutions of the Langevin equation for nonlinear potentials for a wide range of noise correlation, strength and temperature down to the vacuum limit.
Abstract: Based on a coherent state representation of noise operator and an ensemble averaging procedure using Wigner canonical thermal distribution for harmonic oscillators, a generalized quantum Langevin equation has been recently developed [Phys. Rev. E 65, 021109 (2002); 66, 051106 (2002)] to derive the equations of motion for probability distribution functions in c-number phase-space. We extend the treatment to explore several systematic approximation schemes for the solutions of the Langevin equation for nonlinear potentials for a wide range of noise correlation, strength and temperature down to the vacuum limit. The method is exemplified by an analytic application to harmonic oscillator for arbitrary memory kernel and with the help of a numerical calculation of barrier crossing, in a cubic potential to demonstrate the quantum Kramers’ turnover and the quantum Arrhenius plot.
54 citations
TL;DR: In this article, the escape rate from a meta stable state for coloured and correlated noise driven open systems based on the Fokker-Planck description of the stochastic process was calculated.
Abstract: In this paper we have calculated the escape rate from a meta stable state for coloured and correlated noise driven open systems based on the Fokker–Planck description of the stochastic process. We consider the effect of two correlation times due to the additive coloured noise and the correlation between additive coloured and multiplicative white noises. The effect of the noise correlation strength on the rate has also been investigated.
24 citations
TL;DR: Based on the Fokker-Planck description of non-Markovian stochastic process in higher dimension and Schwartz inequality principle, upper bound of rate of entropy change for the thermodynamically closed systems is calculated.
Abstract: Based on the Fokker-Planck description of non-Markovian stochastic process in higher dimension and the Schwartz inequality principle, we have calculated upper bound of rate of entropy change for the thermodynamically closed systems. The interplay of frictional memory kernel and noise-correlation time reveals extremal nature of the upper bound.