Quantum transport in semiconductor-superconductor microjunctions

TL;DR

This paper reviews the current understanding of quantum transport phenomena in semiconductor-superconductor microjunctions, emphasizing a scattering theory framework that identifies phase-coherent Andreev reflection signatures across various mesoscopic systems.

Contribution

It introduces a scattering theory that generalizes Landauer's formula to describe conductance in semiconductor-superconductor junctions, highlighting phase-coherent effects.

Findings

Identification of conductance signatures of Andreev reflection

Application of theory to quantum point contacts and quantum dots

Analysis of phenomena like weak localization and shot noise

Abstract

Recent experiments on conduction between a semiconductor and a superconductor have revealed a variety of new mesoscopic phenomena. Here is a review of the present status of this rapidly developing field. A scattering theory is described which leads to a conductance formula analogous to Landauer's formula in normal-state conduction. The theory is used to identify features in the conductance which can serve as "signatures" of phase-coherent Andreev reflection, i.e. for which the phase coherence of the electrons and the Andreev-reflected holes is essential. The applications of the theory include a quantum point contact, quantum dot, weak localization, universal conductance fluctuations, shot noise, and reflectionless tunneling. This review is based on lectures at the Les Houches summer school, Session LXI, 1994.