Time-dependent quantum transport: A practical scheme using density functional theory
摘要
We present a computationally tractable scheme of time-dependent transport phenomena within open-boundary time-dependent density-functional-theory. Within this approach all the response properties of a system are determined from the time-propagation of the set of ``occupied'' Kohn-Sham orbitals under the influence of the external bias. This central idea is combined with an open-boundary description of the geometry of the system that is divided into three regions: left/right leads and the device region (``real simulation region''). We have derived a general scheme to extract the set of initial states in the device region that will be propagated in time with proper transparent boundary-condition at the device/lead interface. This is possible due to a new modified Crank-Nicholson algorithm that allows an efficient time-propagation of open quantum systems. We illustrate the method in one-dimensional model systems as a first step towards a full first-principles implementation. In particular we show how a stationary current develops in the system independent of the transient-current history upon application of the bias. The present work is ideally suited to study ac transport and photon-induced charge-injection. Although the implementation has been done assuming clamped ions, we discuss how it can be extended to include dissipation due to electron-phonon coupling through the combined simulation of the electron-ion dynamics as well as electron-electron correlations.
引用
@article{arxiv.cond-mat/0502391,
title = {Time-dependent quantum transport: A practical scheme using density functional theory},
author = {S. Kurth and G. Stefanucci and C. -O. Almbladh and A. Rubio and E. K. U. Gross},
journal= {arXiv preprint arXiv:cond-mat/0502391},
year = {2009}
}
备注
14 pages, 9 figures, one of which consist of two separate files