Manipulation of local nuclear spin polarization in quantum Hall systems

We demonstrate a spatially resolved detection of dynamic nuclear polarization (DNP) in integer quantum Hall systems. A continuous-wave radio-frequency (RF) magnetic field is generated by transmitting RF electrical current through micro-metal strips fabricated on top of a Hall bar device. Nuclear magnetic resonance (NMR) in a limited region along edge channels is detected via the edge-channel transport. Systematic difference of the NMR amplitudes from different regions provides an evidence of the local detection of DNP.