A reduced-order modeling approach for electron transport in molecular junctions

TL;DR

This paper introduces a reduced-order modeling approach for simulating electron transport in molecular junctions, enabling efficient analysis of non-equilibrium quantum processes with open boundary conditions.

Contribution

It develops a systematic Petrov-Galerkin projection method to derive reduced models that accurately capture transient and steady states in quantum transport.

Findings

Reduced models effectively reproduce transient dynamics.

Steady-state behaviors are accurately captured.

Method simplifies complex quantum transport calculations.

Abstract

To describe non-equilibrium transport processes in a quantum device with infinite baths, we propose to formulate the problems as a reduced-order problem. Starting with the Liouville-von Neumann equation for the density-matrix, the reduced-order technique yields a finite system with open boundary conditions. We show that with appropriate choices of subspaces, the reduced model can be obtained systematically from the Petrov-Galerkin projection. The self-energy associated with the bath emerges naturally. The results from the numerical experiments indicate that the reduced models are able to capture both the transient and steady states.