Anisotropic Pauli spin-blockade effect and spin-orbit interaction field in an InAs nanowire double quantum dot

TL;DR

This paper experimentally detects the spin-orbit interaction field in an InAs nanowire double quantum dot, revealing its orientation and dominance in spin state mixing, which is crucial for quantum device applications.

Contribution

First experimental detection of an off-substrate-plane spin-orbit field in an InAs nanowire, advancing understanding of spin interactions in quantum dots.

Findings

Spin-orbit interaction dominates at finite magnetic fields.

The spin-orbit field is perpendicular to the nanowire axis.

First observation of off-substrate-plane spin-orbit field in InAs nanowires.

Abstract

We report on experimental detection of the spin-orbit interaction field in an InAs nanowire double quantum dot device. In the spin blockade regime, leakage current through the double quantum dot is measured and is used to extract the effects of spin-orbit interaction and hyperfine interaction on spin state mixing. At finite magnetic fields, the leakage current arising from the hyperfine interaction is suppressed and the spin-orbit interaction dominates spin state mixing. We observe dependence of the leakage current on the applied magnetic field direction and determine the direction of the spin-orbit interaction field. We show that the spin-orbit field lies in a direction perpendicular to the nanowire axis but with a pronounced off-substrate-plane angle. It is for the first time that such an off-substrate-plane spin-orbit field in an InAs nanowire has been detected. The results are expected to have an important implication in employing InAs nanowires to construct spin-orbit qubits and topological quantum devices.