Time-Loop Formalism for Irreversible Quantum Problems: Steady State Transport in Junctions with Asymmetric Dynamics

TL;DR

This paper introduces a novel formalism based on time-loop techniques within the Schwinger-Keldysh framework to analyze steady-state transport in quantum junctions characterized by asymmetric, non-Hermitian dynamics, capturing irreversibility.

Contribution

It presents a general scheme for non-Hermitian quantum systems using the Schwinger-Keldysh formalism, demonstrated through a model of asymmetric quantum junctions.

Findings

Effective description of irreversibility in quantum transport

Application of the formalism to asymmetric junctions

Insights into steady-state behavior with non-Hermitian Hamiltonians

Abstract

Non-unitary quantum mechanics has been used in the past to study irreversibility, dissipation and decay in a variety of physical systems. In this letter, we propose a general scheme to deal with systems governed by non-Hermitian Hamiltonians. We argue that the Schwinger-Keldysh formalism gives a natural description for those problems. To elucidate the method, we study a simple model inspired by mesoscopic physics --an asymmetric junction. The system is governed by a non-Hermitian Hamiltonian which captures essential aspects of irreversibility.