Characterization of one-dimensional quantum channels in InAs/AlSb

TL;DR

This study investigates the magnetoresistance and ballistic transport phenomena in one-dimensional InAs quantum channels, revealing unique properties and quantum interference effects due to nanoscale confinement and fabrication techniques.

Contribution

It introduces a novel nanofabrication method for InAs quantum channels and characterizes their ballistic transport and quantum interference properties at low temperatures.

Findings

Observation of ballistic transport phenomena such as negative bend resistance and Hall resistance quenching.

Detection of Aharonov-Bohm interference with distinct characteristics from GaAs systems.

Identification of specular boundary scattering and strong lateral confinement in the channels.

Abstract

We report the magnetoresistance characteristics of one-dimensional electrons confined in a single InAs quantum well sandwiched between AlSb barriers. As a result of a novel nanofabrication scheme that utilizes a 3nm-shallow wet chemical etching to define the electrostatic lateral confinement, the system is found to possess three important properties: specular boundary scattering, a strong lateral confinement potential, and a conducting channel width that is approximately the lithography width. Ballistic transport phenomena, including the quenching of the Hall resistance, the last Hall plateau, and a strong negative bend resistance, are observed at 4K in cross junctions with sharp corners. In a ring geometry, we have observed Aharonov-Bohm interference that exhibits characteristics different from those of the GaAs counterpart due to the ballistic nature of electron transport and the narrowness of the conducting channel width.