Quantum transport: The link between standard approaches in superlattices

TL;DR

This paper introduces a quantum transport model using nonequilibrium Green functions that unifies and extends existing theories of electrical transport in semiconductor superlattices, covering previously inaccessible parameter regions.

Contribution

The paper develops a comprehensive quantum transport model that reproduces traditional theories and explores new parameter regimes in superlattice transport.

Findings

Unified framework for superlattice transport theories

Reproduces miniband, hopping, and tunneling regimes

Explores novel transport behaviors in uncharted parameter space

Abstract

Theories describing electrical transport in semiconductor superlattices can essentially be divided in three disjoint categories: i) transport in a miniband; ii) hopping between Wannier-Stark ladders; and iii) sequential tunneling. We present a quantum transport model, based on nonequilibrium Green functions, which, in the appropriate limits, reproduces the three conventional theories, and describes the transport in the previously unaccessible region of the parameter space.