Memory effect preserved time-local approach to noise spectrum of transport current

TL;DR

This paper introduces a time-local method based on second-order non-Markovian master equations to efficiently compute the noise spectrum in interacting mesoscopic systems, capturing energy emission and absorption details.

Contribution

It presents a novel, practical approach for calculating the full noise spectrum, including asymmetries, in nonequilibrium quantum transport with electron interactions and memory effects.

Findings

Method agrees well with exact results across various parameters

Successfully characterizes energy emission and absorption in transport

Efficiently handles electron-electron Coulomb interactions

Abstract

Within the second-order non-Markovian master equation description, we develop an efficient method for calculating the noise spectrum of transport current through interacting mesoscopic systems. By introducing proper current-related density operators, we propose a practical and very efficient time-local approach to compute the noise spectrum, including the asymmetric spectrum, which contains the full information of energy emission and absorption. We obtain an analytical formula of the current noise spectrum to characterize the nonequilibrium transport including electron-electron Coulomb interaction and the memory effect. We demonstrate the proposed method in transport through interacting-quantum-dots system, and find good agreement with the exact results under broad range of parameters.