Disentangling the effects of spin-orbit and hyperfine interactions on spin blockade

TL;DR

This paper investigates how spin-orbit and hyperfine interactions influence spin blockade in InAs nanowire double quantum dots, providing a detailed understanding of their individual effects through experimental measurements and modeling.

Contribution

It presents the first detailed separation and quantification of spin-orbit and hyperfine effects on spin blockade in InAs nanowire quantum dots.

Findings

Spin blockade occurs for the first two half-filled orbitals.

Partial lifting of spin blockade is caused by spin-orbit and hyperfine interactions.

A simple transport model accurately reproduces experimental results.

Abstract

We have achieved the few-electron regime in InAs nanowire double quantum dots. Spin blockade is observed for the first two half-filled orbitals, where the transport cycle is interrupted by forbidden transitions between triplet and singlet states. Partial lifting of spin blockade is explained by spin-orbit and hyperfine mechanisms that enable triplet to singlet transitions. The measurements over a wide range of interdot coupling and tunneling rates to the leads are well reproduced by a simple transport model. This allows us to separate and quantify the contributions of the spin-orbit and hyperfine interactions.