Physics & Astronomy ETDs
Publication Date
Fall 12-5-2016
Abstract
This dissertation is a report on a number of distinct topics in the field of non-equilibrium statistical mechanics including the evolution of classical as well as quantum systems.
The evolution of an object that is described by the Ornstein-Uhlenbeck process generalized through a time-nonlocal attraction is considered. The time-nonlocality is taken to be represented in the Langevin description through the presence of memory. Analysis of the Langevin equation is performed for algebraic and delay-type memories. An equivalent \emph{bona-fide} Fokker-Planck equation is constructed.
A random walker subjected to a non-standard confining potential, taken to be a piece-wise linear function, is analyzed. Matching conditions for arbitrary joining configurations are given. Exact propagators in both the time- and Laplace-domains are derived for the case of a `V'-shaped potential. Two illustrative applications of such calculations are presented in the areas of chemical physics and biophysics.
The relaxation of quantum systems interacting with a thermal reservoir is studied. Calculations for specified bath spectral functions are presented. Our primary focus is the vibrational relaxation of an excited molecule and we provide a generalization of the Montroll-Shuler equation into the coherent domain. A related system, the Stark ladder, is briefly discussed.
Degree Name
Physics
Level of Degree
Doctoral
Department Name
Physics & Astronomy
First Committee Member (Chair)
Vasudev Kenkre
Second Committee Member
Sudhakar Prasad
Third Committee Member
Dinesh Loomba
Fourth Committee Member
Luca Giuggioli
Language
English
Document Type
Thesis
Recommended Citation
Chase, Matthew. "Memory Effects in Brownian Motion, Random Walks under Confining Potentials, and Relaxation of Quantum Systems." (2016). https://digitalrepository.unm.edu/phyc_etds/106
Included in
Astrophysics and Astronomy Commons, Statistical, Nonlinear, and Soft Matter Physics Commons