Spin polarization of fractional quantum Hall edge channels studied by dynamic nuclear polarization

We find that the scattering between unequally populated fractional quantum Hall (FQH) edge channels (EC's) polarizes nuclear spins through the hyperfine interaction. This dynamic nuclear polarization (DNP) is evidenced by the nuclear magnetic resonance detected via the transport through FQH EC's. Spin polarizations of different FQH EC's are inferred from the polarity of DNP.