1304.3257 (Rui Li et al.)

Determination of the spin-orbit coupling in a nanowire via
electric-dipole spin resonance    [PDF]

Rui Li, J. Q. You, C. P. Sun, Franco Nori

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 a.c. 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 a.c. 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.

View original: http://arxiv.org/abs/1304.3257