Nonequilibrium transport and optical properties of model metal--Mott-insulator--metal heterostructures

TL;DR

This paper investigates the electronic and optical properties of metal–Mott-insulator–metal heterostructures under bias voltage using advanced theoretical methods, revealing measurable spectral and conductivity changes.

Contribution

It combines dynamical mean-field theory with Keldysh Green's functions to analyze nonequilibrium transport and optical responses in correlated heterostructures, providing new insights into their behavior.

Findings

Bias voltage alters electron spectral functions.

Optical conductivity changes can indicate density of states deformation.

Measurable effects via photoemission and tunneling microscopy.

Abstract

Electronic properties of heterostructures in which a finite number of Mott-insulator layers are sandwiched by semi-infinite metallic leads are investigated by using the dynamical-mean-field method combined with the Keldysh Green's function technique to account for the finite bias voltage between the leads. Current across the junction is computed as a function of bias voltage. Electron spectral functions in the interacting region are shown to evolve by an applied bias voltage. This effect is measurable by photoemission spectroscopy and scanning tunneling microscopy. Further predictions are made for the optical conductivity under a bias voltage as a possible tool to detect a deformed density of states. A general discussion of correlated-electron based heterostructures and future prospect is given.