Single-electron spin resonance in a g-factor-controlled semiconductor quantum dot

We demonstrate that a single electron spin in a quantum dot, of which g-factor is tuned to nearly zero, is coherently manipulated by the local gate operation. A nearly zero electron g-factor is essential for the quantum state transfer from a photon to an electron spin and ideal for long electron spin memory. The g-factor was tuned by replacing the single heterostructure, which forms the conventional quantum dot, into a single quantum well with a proper electron confinement. The obtained electron g-factor was about 0.05, which is consistent with the optically estimated g-factor. We also demonstrate that the Rabi oscillation was maintained for more than 1.5 μs.