The electron spin in a semiconductor quantum dot can be coherently controlled by an external electric field, an effect called electric-dipole spin resonance (EDSR). Several mechanisms can give rise to the EDSR effect, among which there is a hyperfine mechanism, where the spin-electric coupling is mediated by the electron-nucleus hyperfine interaction. Here, we investigate the influence of frequency modulation (FM) on the spin-flip efficiency. Our results reveal that FM plays an important role in the hyperfine mechanism. Without FM, the electric field almost cannot flip the electron spin; the spin-flip probability is only about 20%. While under FM, the spin-flip probability can be improved to approximately 70%. In particular, we find that the modulation amplitude has a lower bound, which is related to the width of the fluctuated hyperfine field.
@article{arxiv.1511.06503,
title = {Hyperfine interaction mediated electric-dipole spin resonance: the role of frequency modulation},
author = {Rui Li},
journal= {arXiv preprint arXiv:1511.06503},
year = {2016}
}