Spin orbit coupling at the level of a single electron

TL;DR

This paper investigates spin-orbit coupling effects at the single-electron level in quantum dots, revealing that a small percentage of tunneling events involve spin flips due to spin-orbit interactions, with high measurement fidelity.

Contribution

It demonstrates a method to distinguish spin-flip tunneling events from spin-conserving ones using electron counting in quantum dots, highlighting the role of spin-orbit coupling.

Findings

Up to 4% of tunneling events involve spin flips.

Measurement fidelity of 99% in detecting spin flips.

Spin-orbit coupling influences tunneling processes in GaAs quantum dots.

Abstract

We utilize electron counting techniques to distinguish a spin conserving fast tunneling process and a slower process involving spin flips in AlGaAs/GaAs-based double quantum dots. By studying the dependence of the rates on the interdot tunnel coupling of the two dots, we find that as many as 4% of the tunneling events occur with a spin flip related to spin-orbit coupling in GaAs. Our measurement has a fidelity of 99 % in terms of resolving whether a tunneling event occurred with a spin flip or not.