Resistive detection of optically pumped nuclear polarization with spin phase transition peak at Landau level filling factor 2/3

Nuclear spins in a single quantum well are polarized by optical pumping and its polarization is detected by resistance change in quantum Hall regime, that is, a shift in the resistance peak of the spin-phase-transition at Landau level filling factor 2/3. The resistive readout of optical nuclear polarization is directly confirmed from resonant features by applying an RF magnetic field. The obtained nuclear magnetic field is at least 0.62 T. The dependence of the peak shift on laser polarization, intensity, duration time, and illumination position shows the sensitivity of polarization distribution and the capability to control optical nuclear orientation.