Dissipative quantum transport at arbitrary parameter regime: a variational method
Abstract
Recent development of theoretical method for dissipative quantum transport have achieved notable progresses in the weak or strong electron-phonon coupling regime. However, a generalized theory for dissipative quantum transport at arbitrary parameter regime is not figured out until now. In this work, a variational method for dissipative quantum transport at arbitrary electron-phonon coupling regime is developed by employing variational polaron theory. The optimal polaron transformation is determined by the optimization of the Feynman-Bogoliubov upper bound of free energy. % which is variational in nature. The free energy minimization ends up with an optimal mean-field Hamiltonian and a minimal interaction Hamiltonian. Hence, second-order perturbation can be applied to the transformed system, resulting an accurate and efficient method for the treatment of dissipative quantum transport with arbitrary electron-phonon coupling strength. Numerical benchmark calculation on an single site model with coupling to one phonon mode is also presented.
Cite
@article{arxiv.1501.01317,
title = {Dissipative quantum transport at arbitrary parameter regime: a variational method},
author = {Yu Zhang and ChiYung Yam and YanHo Kwok and GuanHua Chen},
journal= {arXiv preprint arXiv:1501.01317},
year = {2015}
}