Resonance Effects in Correlated Multilayer Heterostructures

TL;DR

This paper investigates how resonance effects induce negative differential conductance in correlated multilayer heterostructures using non-equilibrium dynamical mean-field theory, revealing specific parameter conditions for resonance tunneling.

Contribution

It introduces a detailed model combining correlated and non-correlated layers and applies advanced non-equilibrium DMFT with an auxiliary master equation solver to analyze resonance-induced conductance phenomena.

Findings

Resonance tunneling occurs at specific parameter values.

Negative differential conductance is observed due to resonance effects.

The study provides detailed current-voltage characteristics influenced by resonance.

Abstract

We study the occurrence of negative differential conductance induced by resonance effects in a model for a multilayer heterostructure. In particular, we consider a system consisting of several correlated and non-correlated monoatomic layers, sandwiched between two metallic leads. The geometry confines electrons in wells within the heterostructures, which are connected to each other and to the leads by tunneling processes. The non-equilibrium situation is produced by applying a bias-voltage to the leads. Our results show that for specific values of the parameters resonance tunneling takes place. We investigate in detail its influence on the current-voltage characteristics. Our results are obtained via non-equilibrium real-space dynamical mean-field theory. As an impurity solver we use the so-called auxiliary master equation approach, which addresses the impurity problem within an auxiliary system consisting of a correlated impurity, a small number of uncorrelated bath sites, and two Markovian environments described by a generalized master equation.