Resistive detection of nuclear spins in a single quantum dot under Kondo effect regime

We study dynamic polarization and resistive detection of nuclear spins in a semiconductor quantum dot (QD) under the Kondo effect regime. We find that the differential conductance spectra of the QD exhibit hysteresis under the Kondo effect regime in magnetic fields. Relevance of nuclear spins to the hysteresis is confirmed by the detection of nuclear magnetic resonance signals by monitoring the differential conductance. We attribute the origin of the hysteresis to the dynamic nuclear spin polarization (DNP) induced in the QD. Using the DNP, we demonstrate nuclear spin relaxation rate measurements in the QD under the Kondo effect regime.