Determination of $g$-factor in InAs two-dimensional electron system by capacitance spectroscopy

TL;DR

This paper introduces a novel capacitance spectroscopy method to accurately determine the effective g-factor and mass of electrons in an InAs 2DEG, revealing strain effects and offering an alternative to traditional techniques.

Contribution

The paper presents a new capacitance spectroscopy approach for measuring the g-factor and effective mass in 2DEGs, highlighting strain influences and providing a complementary method to existing techniques.

Findings

Capacitance spectroscopy reveals Zeeman splitting in InAs 2DEG.

Strain significantly affects effective mass and g-factor.

Method offers an independent measurement of electronic parameters.

Abstract

We determine the effective $g$-factor ($|g^\ast|$) of a two-dimensional electron gas (2DEG) using a new method based on capacitance spectroscopy. The capacitance-voltage profile of a 2DEG in an InAs/AlGaSb quantum well measured in an in-plane magnetic field shows a double-step feature that indicates the Zeeman splitting of the subband edge. The method allows for simultaneous and independent determination of $|g^\ast|$ and effective mass $m^\ast$. Data suggest that the biaxial tensile strain in the InAs layer has considerable impacts on both $m^\ast$ and $g^\ast$. Our method provides a means to determine $|g^\ast|$ that is complementary to the commonly used coincidence technique.