Coherent control of a single electron spin with electric fields

Manipulation of single spins is essential for spin-based quantum information processing. Electrical control instead of magnetic control is particularly appealing for this purpose, since electric fields are easy to generate locally on-chip. We experimentally realize coherent control of a single electron spin in a quantum dot using an oscillating electric field generated by a local gate. The electric field induces coherent transitions (Rabi oscillations) between spin-up and spin-down with pi/2 rotations as fast as ~55ns. Our analysis indicates that the electrically-induced spin transitions are mediated by the spin-orbit interaction. Taken together with the recently demonstrated coherent exchange of two neighboring spins, our results demonstrate the feasibility of fully electrical manipulation of spin qubits.