Spin blockade as a probe of Zeeman interactions in hole quantum dots

TL;DR

This paper explores how spin blockade in hole quantum dots reveals the anisotropic effects of Zeeman and spin-orbit couplings, offering insights for quantum control and magnetic interaction tuning.

Contribution

It demonstrates how the interplay of Zeeman and spin-orbit couplings affects spin blockade leakage and provides methods to control magnetic interactions via field orientation.

Findings

Leakage current is anisotropic and depends on magnetic field direction.

The period of leakage anisotropy depends on Zeeman interaction terms.

Field orientation can tune singlet-triplet splitting and magnetic interactions.

Abstract

Spin-orbit coupling is key to all-electrical control of quantum-dot spin qubits, and is frequently stronger for holes than for electrons. Here we investigate Pauli spin blockade for two heavy holes in a gated double quantum dot in an in-plane magnetic field. The interplay of the complex Zeeman and spin-orbit couplings causes a blockade leakage current anisotropic in the field direction. The period of the anisotropic leakage is critically dependent on the relative magnitude of Zeeman interaction terms linear and cubic in the magnetic field. The current and singlet-triplet exchange splitting can be effectively adjusted by an appropriate choice of field direction, providing a simple control variable for quantum information processing and a way of tailoring magnetic interactions in hole spin qubits.