Calculation of the current noise spectrum in mesoscopic transport: an efficient quantum master equation approach

TL;DR

This paper introduces an efficient quantum master equation method for calculating the current noise spectrum in mesoscopic transport, effectively handling many-body interactions and quantum coherence with simplicity compared to traditional techniques.

Contribution

It presents a novel approach that combines advantages of classical rate equations and quantum trajectory methods for noise spectrum calculation in quantum transport.

Findings

The method accurately captures Coulomb interactions and quantum coherence.

It simplifies calculations compared to Landauer-Büttiker and Green's function methods.

Demonstrates practical efficiency through multiple examples.

Abstract

Based on our recent work on quantum transport [Li et al., Phys. Rev. B 71, 205304 (2005)], where the calculation of transport current by means of quantum master equation was presented, in this paper we show how an efficient calculation can be performed for the transport noise spectrum. Compared to the longstanding classical rate equation or the recently proposed quantum trajectory method, the approach presented in this paper combines their respective advantages, i.e., it enables us to tackle both the many-body Coulomb interactionand quantum coherence on equal footing and under a wide range of setup circumstances. The practical performance and advantages are illustrated by a number of examples, where besides the known results and new insights obtained in a transparent manner, we find that this alternative approach is much simpler than other well-known full quantum mechanical methods such as the Landauer-B\"uttiker scattering matrix theory and the nonequilibrium Green's function technique.