Nonequilibrium Steady States and MacLennan-Zubarev Ensembles in a Quantum Junction System

TL;DR

This paper constructs a nonequilibrium steady state for a quantum dot system interacting with reservoirs, demonstrating its relation to MacLennan-Zubarev ensembles and deriving response-correlation relations.

Contribution

It develops a practical method to construct NESS in quantum systems and links it to established ensemble frameworks, extending previous theoretical approaches.

Findings

NESS can be modeled as a MacLennan-Zubarev ensemble.

Response and correlation functions are formally related at NESS.

Application to an Aharonov-Bohm ring with a quantum dot illustrates the theory.

Abstract

Based on a recent progress in nonequilibrium statistical mechanics of infinitely extended quantum systems, a nonequlibrium steady state (NESS) is constructed for a single-level quantum dot interacting with two free reservoirs under less general but more practically useful conditions than the previous works. As an example, a model of an Ahoronov-Bohm ring with a quantum dot is studied in detail. Then, NESS is shown to be regarded as a MacLennan-Zubarev ensemble. A formal relation between response and correlation at NESS is derived as well.