Decoherence of nuclear spins due to direct dipole-dipole interactions probed by resistively detected nuclear magnetic resonance

摘要

We study decoherence of nuclear spins in a GaAs quantum well structure usingresistively detected nuclear magnetic resonance. The transverse decoherencetime T2 of 75As nuclei is estimated from Rabi-type coherent oscillations aswell as by using spin-echo techniques. By analyzing T2 obtained by decouplingtechniques, we extract the role of dipole-dipole interactions as sources ofdecoherence in GaAs. Under the condition that the device is tilted in anexternal magnetic field, we exhibit enhanced decoherence induced by the changein strength of the direct dipole-dipole interactions between firstnearest-neighbor nuclei. The results agree well with simple numericalcalculations.