arXiv subjects

Chinmoy Samanta

Publications and source records attributed to Chinmoy Samanta.

4 recordsLinked to original sources

arXiv2020

Transition time estimation for $δ$-function coupling in two state problem: An analytically solvable model

We propose a simple method to calculate transition time in a two-state scattering problem, where two constant potentials are coupled by a delta function potential $V_{12}=V_{21}=k_0 δ(x)$. The exact analytical expression for the time of transition $τ$ is derived. We notice $τ$ explicitly depends on the second state's potential energy along with the incident energy and coupling strength. We also observe from the derived expression of $τ$ that depending on the initial energy, the coupling potential could behave like a transparent or opaque medium to the incident wave in a single state equivalent description.

quant-ph↗

arXiv2020

Reaction-diffusion dynamics through a Gaussian sink in the presence of an attractive stepwise linear potential energy curve

In the present report, we have introduced the Fredholm integral method to solve the Smoluchowski equation in the Laplace domain. We get an exact semi-analytical solution for the linear potential energy curve in the dynamic diffusion process, and the survival probability is calculated by the numerical inverse Laplace transform method. We apply our method in two different physical contexts for finding different observable like average rate constant in electronic relaxation in solution and quantum yields in a photosynthetic system or doped molecular crystal.

physics.chem-ph↗

arXiv2019

Reaction-Diffusion dynamics in presence of active barrier: Pinhole sink

In this article, we give a semi-analytic expression for survival probability when particles are diffusing in an active potential well. There is no analytic solution available in the literature, due to the requirement of inverse Laplace transform of the propagator, when a sink is placed at the uphill of the parabolic potential even in case of the localized sink. We also explain some of the physical aspects by using our solution.

cond-mat.stat-mech↗

arXiv2019

A new approach in an analytical method for diffusion dynamics for the presence of delocalized sink in a potential well: Application to different potential curves

We provide a new approach to solve one dimension Fokker-Planck equation in the Laplace domain for the case where a particle is evolving in a potential energy curve in the presence of general delocalized sink. We also calculate rate constants in the presence of non-localized sink on different potential energy curves. In the previous method, we need to solve matrix equations to calculate rate constant but in our method, it is not required. We also calculate the rate constant by using the method to some known potential curve, viz, flat potential, linear potential, and parabolic potential.

physics.chem-ph↗