Controlling a nanowire spin-orbit qubit via electric-dipole spin resonance

• Published in: Physical review letters Vol. 111; no. 8; p. 086805
• Main Authors: Li, Rui, You, J Q, Sun, C P, Nori, Franco
• Format: Journal Article
• Language: English
• Published: United States 23.08.2013
• ISSN: 1079-7114
• DOI: 10.1103/physrevlett.111.086805

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 η(opt)=√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.