Controlling a Nanowire Spin-Orbit Qubit via Electric-Dipole Spin Resonance

TL;DR

This paper develops a theory for controlling nanowire spin-orbit qubits using electric-dipole spin resonance, revealing optimal SOC strength and magnetic field direction effects for enhanced qubit manipulation.

Contribution

It introduces a comprehensive theory for strong SOC regimes in nanowire qubits, identifying optimal SOC strength and magnetic field orientation effects.

Findings

Maximum Rabi frequency at SOC strength η_{opt} = √2/2

Periodic responses of level spacing and Rabi frequency to magnetic field direction

Method to determine SOC strength via resonance responses

Abstract

A semiconductor nanowire quantum dot with strong spin-orbit coupling (SOC) can be used to achieve a spin-orbit qubit. In contrast to a spin qubit, the spin-orbit qubit can respond to an external ac electric field, an effect called electric-dipole spin resonance. Here we develop a theory that can apply in the strong SOC regime. We find that there is an optimal SOC strength \eta_{opt}=\sqrt{2}/2, where the Rabi frequency induced by the ac electric field becomes maximal. Also, we show that both the level spacing and the Rabi frequency of the spin-orbit qubit have periodic responses to the direction of the external static magnetic field. These responses can be used to determine the SOC in the nanowire.