Electrical Detection of Nuclear Magnetic Resonance Signal of Nuclear Spins of Order 104 in a Semiconductor Double Quantum Dot

We report the electrical detection of a nuclear magnetic resonance signal of indium spins in a vertical GaAs/In0.04Ga0.96As double quantum dot. In this system, dynamic nuclear polarization appears to be accompanied by a relief of the Pauli spin-blockade state, and can be detected as a change in the current if a radio-frequency magnetic field is applied. We observed a change in the current under a dc magnetic field, and detected an NMR signal with ~2×104 indium spins as this change in the resonant frequency. A difference in polarization between two dots can be obtained with the depolarization of indium.