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

摘要

We study decoherence of nuclear spins in a GaAs quantum well structure using resistively detected nuclear magnetic resonance. The transverse decoherence time T_2 of ~(75)As nuclei is estimated from Rabi-type coherent oscillations as well as by using spin-echo techniques. By analyzing T_2 obtained by decoupling techniques, we extract the role of dipole-dipole interactions as sources of decoherence in GaAs. Under the condition that the device is tilted in an external magnetic field, we exhibit enhanced decoherence induced by the change in strength of the direct dipole-dipole interactions between first nearest-neighbor nuclei. The results agree well with simple numerical calculations.