Spectroscopy of spin-orbit quantum bits in indium antimonide nanowires

TL;DR

This study investigates the spin-orbit interaction in InSb nanowire double quantum dots by analyzing two-electron states through electric dipole spin resonance, revealing the magnitude and orientation of the spin-orbit field.

Contribution

It provides a detailed characterization of spin-orbit effects in InSb nanowire quantum dots using multiple spectroscopic techniques, advancing understanding of spin control in quantum computing.

Findings

Observation of singlet-triplet level repulsion due to spin-orbit interaction

Determination of the magnitude and orientation of the spin-orbit effective field

Confirmation of results through spin blockade leakage current anisotropy

Abstract

Double quantum dot in the few-electron regime is achieved using local gating in an InSb nanowire. The spectrum of two-electron eigenstates is investigated using electric dipole spin resonance. Singlet-triplet level repulsion caused by spin-orbit interaction is observed. The size and the anisotropy of singlet-triplet repulsion are used to determine the magnitude and the orientation of the spin-orbit effective field in an InSb nanowire double dot. The obtained results are confirmed using spin blockade leakage current anisotropy and transport spectroscopy of individual quantum dots.