Aharonov-Bohm oscillations and electron gas transitions in hexagonal core-shell nanowires with an axial magnetic field

TL;DR

This study models electronic states in GaAs/InAs core-shell nanowires under axial magnetic fields, revealing Aharonov-Bohm oscillations and charge/spin transitions with implications for magnetoconductance experiments.

Contribution

It provides a comprehensive 3D quantum model including realistic geometry, electrostatics, and magnetic effects, advancing understanding of nanowire electronic behavior under magnetic fields.

Findings

Observation of Aharonov-Bohm oscillations at low fields

Identification of charge and spin transitions at high fields

Predictions of magnetoconductance signatures for experimental validation

Abstract

We use spin-density-functional theory within an envelope function approach to calculate electronic states in a GaAs/InAs core-shell nanowire pierced by an axial magnetic field. Our fully 3D quantum modeling includes explicitly the description of the realistic cross-section and composition of the sample, and the electrostatic field induced by external gates in two different device geometries, gate-all-around and back-gate. At low magnetic fields, we investigate Aharonov-Bohm oscillations and signatures therein of the discrete symmetry of the electronic system, and we critically analyze recent magnetoconductance observations. At high magnetic fields we find that several charge and spin transitions occur. We discuss the origin of these transitions in terms of different localization and Coulomb regimes and predict their signatures in magnetoconductance experiments.