In_(0.75)Ga_(0.25)As on GaAs submicron rings and their application for coherent nanoelectronic devices

TL;DR

This paper demonstrates the fabrication and operation of submicron InGaAs/AlInAs Aharonov-Bohm rings that exhibit electron-phase modulation, high reproducibility, and potential for coherent nanoelectronic devices operable at accessible temperatures.

Contribution

It introduces a novel fabrication scheme for InGaAs rings with radii below 200 nm, enabling coherent electronic circuits without cryogenic liquids.

Findings

High-contrast oscillations observed in AB rings

Reproducible fabrication process developed

Devices operate with closed-cycle refrigeration

Abstract

Electron-phase modulation in magnetic and electric fields will be presented in In_(0.75)Ga_(0.25)As Aharonov-Bohm (AB) rings. The zero Schottky barrier of this material made it possible to nanofabricate devices with radii down to below 200 nm without carrier depletion. We shall present a fabrication scheme based on wet and dry etching that yielded excellent reproducibility, very high contrast of the oscillations and good electrical gating. The operation of these structures is compatible with closed-cycle refrigeration and suggests that this process can yield coherent electronic circuits that do not require cryogenic liquids. The InGaAs/AlInAs heterostructure was grown by MBE on a GaAs substrate [1], and in light of the large effective g-factor and the absence of the Schottky barrier is a material system of interest for the investigation of spin-related effects [2-4]} and the realization of hybrid superconductor/semiconductor devices [5].