Nuclear spin population and its control toward initialization using an all-electrical submicron scale nuclear magnetic resonance device

The authors study the nuclear spin population in a GaAs quantum well structure and demonstrate its initialization using an all-electrical nuclear magnetic resonance (NMR) device. In their device, nuclear spins are dynamically polarized in a submicron scale region defined by split gates. The relative population of each nuclear spin state is estimated from resistively detected NMR spectra combined with numerical analysis. They find that nuclear spin populations are determined by electron spin configurations. By applying radio frequency pulses to the strongly polarized nuclear spins, they demonstrate the creation of two-qubit effective pure states, which is a crucial step toward NMR quantum computation.