Anisotropic Zeeman splitting in p-type GaAs quantum point contacts

TL;DR

This study investigates the anisotropic Zeeman splitting in p-type GaAs quantum point contacts through conductance spectroscopy, revealing how confinement anisotropy affects g-factors and aligning experimental results with theoretical predictions.

Contribution

It provides a detailed analysis of Zeeman splitting anisotropy in p-type GaAs quantum point contacts, highlighting the role of confinement potential and improving out-of-plane g-factor estimates.

Findings

In-plane g-factors agree qualitatively with previous quantum wire experiments.

Quantitative differences are explained by confinement anisotropy.

Out-of-plane g-factor estimates are closer to theoretical predictions.

Abstract

Low-temperature electrical conductance spectroscopy measurements of quantum point contacts implemented in p-type GaAs/AlGaAs heterostructures are used to study the Zeeman splitting of 1D subbands for both in-plane and out-of-plane magnetic field orientations. The resulting in-plane g-factors agree qualitatively with those of previous experiments on quantum wires while the quantitative differences can be understood in terms of the enhanced quasi-1D confinement anisotropy. The influence of confinement potential on the anisotropy is discussed and an estimate for the out-of-plane g-factor is obtained which, in contrast to previous experiments, is closer to the theoretical prediction.