Multi-mode Floquet NEGF method for driven quantum transport

TL;DR

This paper introduces a non-perturbative Floquet NEGF method for analyzing electron transport in quantum systems driven by multiple independent periodic forces, enabling detailed study of complex driven quantum phenomena.

Contribution

The paper develops a two-mode Floquet NEGF framework and extends it to multiple drivings, providing a new tool for non-perturbative analysis of driven quantum transport.

Findings

Extra sinusoidal off-diagonal driving significantly modifies current suppression.

The method accurately captures the effects of multiple simultaneous drivings.

The approach is broadly applicable to complex open quantum systems.

Abstract

We present a non-perturbative Floquet-based non-equilibrium Green's function (NEGF) method to study electron transport in a quantum system driven simultaneously by multiple independent terms (multi-mode). We first derive the two-mode Floquet NEGF based on two-step transformations of the retarded-advanced Green's function from the Kadanoff-Baym equation. This derivation proceeds by elaborating on the expectation values of the number and current operators. The two-mode Floquet NEGF is then extended to cases with multiple drivings. The method is tested by investigating current suppression in the presence of two drivings. We show that an extra sinusoidal off-diagonal driving can cause substantial modification to the current suppression, provided careful selection of the driving frequency. Consequently, we expect that the established method has broad applications in a wide range of open quantum systems driven by complicated drivings.