Experimental Measurements of Effective Mass in Near Surface InAs Quantum Wells

TL;DR

This study measures the effective mass of electrons in near surface InAs quantum wells using magnetotransport and cyclotron resonance, revealing magnetic field dependence and band non-parabolicity effects.

Contribution

It provides the first combined magnetotransport and cyclotron resonance measurements of effective mass in near surface InAs quantum wells, highlighting field-dependent behavior.

Findings

Effective mass is approximately 0.04 at low magnetic fields.

Effective mass varies with magnetic field in high-field regime.

Band non-parabolicity explains the mass dependence on magnetic field.

Abstract

Near surface indium arsenide quantum wells have recently attracted a great deal of interest since they can be interfaced epitaxially with superconducting films and have proven to be a robust platform for exploring mesoscopic and topological superconductivity. In this work, we present magnetotransport properties of two-dimensional electron gases confined to an indium arsenide quantum well near the surface. The electron mass extracted from the envelope of the Shubnikov-de Haas oscillations shows an average effective mass $m^{*}$ = 0.04 at low magnetic field. Complementary to our magnetotransport study, we employed cyclotron resonance measurements and extracted the electron effective mass in the ultra high magnetic field regime. Our measurements show that the effective mass depends on magnetic field in this regime. The data can be understood by considering a model that includes non-parabolicity of the indium arsenide conduction bands.