Bound States in Time-Dependent Quantum Transport: Oscillations and Memory Effects in Current and Density

TL;DR

This paper investigates how bound states in nanoscale quantum transport cause persistent current oscillations and density variations that depend on the history of applied potentials, revealing new insights into non-equilibrium quantum systems.

Contribution

It introduces a time-dependent framework to analyze bound states in quantum transport, highlighting their impact on current oscillations and density, and defining bound-state occupations out of equilibrium.

Findings

Bound states cause persistent current oscillations larger than steady current.

Oscillation amplitudes depend on the entire history of applied potentials.

Bound-state contributions to density are also history-dependent.

Abstract

The presence of bound states in a nanoscale electronic system attached to two biased, macroscopic electrodes is shown to give rise to persistent, non-decaying, localized current oscillations which can be much larger than the steady part of the current. The amplitude of these oscillations depends on the entire history of the applied potential. The bound-state contribution to the {\em static} density is history-dependent as well. Moreover, the time-dependent formulation leads to a natural definition of the bound-state occupations out of equilibrium.