Hole transport in p-type GaAs quantum dots and point contacts

TL;DR

This paper investigates hole transport in p-type GaAs quantum dots and point contacts, demonstrating conductance quantization and Coulomb resonances, with implications for spintronic device development.

Contribution

It provides the first detailed transport measurements on p-type GaAs nanostructures fabricated by scanning probe oxidation lithography, highlighting quantum effects and device characteristics.

Findings

Conductance quantization observed in quantum point contact

Pronounced Coulomb resonances in quantum dots

Charging energies consistent with lithographic dimensions

Abstract

Strong spin-orbit interaction characteristic for p-type GaAs systems, makes such systems promising for the realization of spintronic devices. Here we report on transport measurements in nanostructures fabricated on p-type, C-doped GaAs heterostructures by scanning probe oxidation lithography. We observe conductance quantization in a quantum point contact, as well as pronounced Coulomb resonances in two quantum dots with different geometries. Charging energies for both dots, extracted from Coulomb diamond measurements are in agreement with the lithographic dimensions of the dots. The absence of excited states in Coulomb diamond measurements indicates that the dots are in the multi-level transport regime.