Quantum wells with atomically smooth interfaces

TL;DR

This paper reports the fabrication of atomically smooth GaAs quantum wells using a specialized growth technique, resulting in uniform optical properties and enabling detailed study of interface formation at the atomic level.

Contribution

It introduces a novel cleaved-edge overgrowth method with growth-interrupt-anneal to produce atomically smooth quantum wells with uniform optical emission.

Findings

Quantum wells exhibit spatially uniform and spectrally sharp emission.

Adding a fractional monolayer reveals atomic step-edge kinetics.

Method achieves atomically smooth hetero-interfaces without roughness.

Abstract

By a cleaved-edge overgrowth method with molecular beam epitaxy and a (110) growth-interrupt-anneal, we have fabricated a GaAs quantum well exactly 30 monolayers thick bounded by atomically smooth AlGaAs hetero-interfaces without atomic roughness. Micro-photoluminescence imaging of this quantum well indeed shows spatially uniform and spectrally sharp emission over areas of several tens of $\mu$m in extent. By adding a fractional GaAs monolayer to our quantum well we are able to study the details of the atomic step-edge kinetics responsible for flat interface formation.