Gate control, g-factors and spin orbit energy of p-type GaSb nanowire quantum dot devices

TL;DR

This study investigates p-type GaSb nanowire quantum dots, revealing localized gate effects, large tunable g-factors, and significant spin-orbit energies, advancing potential quantum information applications.

Contribution

It demonstrates the localized nature of gate effects in p-GaSb nanowires and characterizes their spin properties, providing insights for quantum device design.

Findings

Gate effects are highly localized, hindering double quantum dot formation.

Large gate-dependent g-factors up to 8.1 were observed.

Spin-orbit energies range from 110 to 230 μeV.

Abstract

Proposals for quantum information applications are frequently based on the coherent manipulation of spins confined to quantum dots. For these applications, p-type III-V material systems promise a reduction of the hyperfine interaction while maintaining large $g$-factors and strong spin-orbit interaction. In this work, we study bottom-gated device architectures to realize single and serial multi-quantum dot systems in Schottky contacted p-type GaSb nanowires. We find that the effect of potentials applied to gate electrodes on the nanowire is highly localized to the immediate vicinity of the gate electrode only, which prevents the formation of double quantum dots with commonly used device architectures. We further study the transport properties of a single quantum dot induced by bottom-gating, find large gate-voltage dependent variations of the $g^*$-factors up to $8.1\pm 0.2$ as well as spin-orbit energies between $110$-$230\,\mu$eV.