Leakage-induced decoherence during single electron spin manipulation in a double quantum dot

Ouyang, Shi-Hua; Lam, Chi-Hang; You, J. Q.

Leakage-induced decoherence during single electron spin manipulation in a double quantum dot

Authors

Ouyang, Shi-Hua

Lam, Chi-Hang

You, J. Q.

Description

Coherent single electron spin oscillation in a double quantum dot system driven by a magnetic electron spin resonance field is studied theoretically using a Bloch-type rate equation approach. The oscillation frequency and relaxation time obtained using typical model parameters are consistent with experiment findings. The dominant decoherence mechanism is identified to be a leakage current through a Coulomb blockade barrier at a quantum dot during the spin manipulation. Nuclear field fluctuations which induce a long relaxation time are found to contribute only negligibly to the decoherence despite an earlier suggestion.
5 pages, 3 figures