Mobility exceeding 100,000 cm$^2$/Vs in modulation-doped shallow InAs quantum wells coupled to epitaxial aluminum

TL;DR

This paper reports achieving extremely high electron mobility exceeding 100,000 cm$^2$/Vs in shallow InAs quantum wells coupled with epitaxial aluminum, advancing the platform for topological superconductivity research.

Contribution

It demonstrates record-high mobility in shallow InAs quantum wells, which is crucial for stabilizing topological phases in hybrid superconductor-semiconductor structures.

Findings

Mobility exceeds 100,000 cm$^2$/Vs at low temperature.

High mobility achieved in shallow InAs quantum wells 10nm below surface.

Potential for improved topological superconductor devices.

Abstract

The two-dimensional electron gas residing in shallow InAs quantum wells coupled to epitaxial aluminum is a widely utilized platform for exploration of topological superconductivity. Strong spin-orbit coupling, large effective $g$-factor, and control over proximity-induced superconductivity are important attributes. Disorder in shallow semiconductor structures plays a crucial role for the stability of putative topological phases in hybrid structures. We report on the transport properties of 2DEGs residing 10nm below the surface in shallow InAs quantum wells in which mobility may exceed 100,000 cm$^2$/Vs at 2DEG density n$_{2DEG}$$\leq$1$\times$10$^{12}$cm$^{-2}$ at low temperature.