Anomalous quantum transport in a thin film

TL;DR

This study numerically investigates electron transport in a thin film with spatially varying disorder, revealing an unconventional increase in current amplitude with disorder strength in the strong disorder regime.

Contribution

It introduces a model for electron transport in a disordered thin film with spatially varying disorder and uncovers anomalous transport behavior.

Findings

Current amplitude increases with disorder in strong disorder regime

Behavior opposite to conventional disordered films

Spatial variation in disorder affects transport properties

Abstract

We present a numerical study of electron transport in a thin film of varying disorder strength with the distance from its surface. A simple tight-binding model is used to describe the system, in which the film is attached to two metallic electrodes and the coupling of this film to the electrodes is illustrated by the Newns-Anderson chemisorption theory. Quite interestingly we observe that, in the smoothly varying disordered film current amplitude increases with the increase of disorder strength in the strong disorder regime, while it decreases in the weak disorder regime. This behavior is completely opposite from a conventional disordered film, where current amplitude always decreases with the increase of disorder strength.