Crossover from tunneling to incoherent (bulk) transport in a correlated nanostructure

TL;DR

This paper investigates how transport mechanisms in a correlated nanostructure transition from tunneling to incoherent bulk conduction, governed by a generalized Thouless energy, depending on barrier thickness and temperature.

Contribution

It introduces a model linking the crossover from tunneling to incoherent transport to a generalized Thouless energy in correlated nanostructures.

Findings

Crossover temperature depends on low-temperature resistance and bulk density of states.

Transport behavior shifts from tunneling to incoherent conduction with increasing barrier thickness.

The generalized Thouless energy effectively describes the crossover dynamics.

Abstract

We calculate the junction resistance for a metal-barrier-metal device with the barrier tuned to lie just on the insulating side of the metal-insulator transition. We find that the crossover from tunneling behavior in thin barriers at low temperature to incoherent transport in thick barriers at higher temperature is governed by a generalized Thouless energy. The crossover temperature can be estimated from the low temperature resistance of the device and the bulk density of states of the barrier.