(color online) Coherent manipulation of a single nuclear spin around an NV center. (a) Pulse sequence. A swap gate is employed to polarize and readout the spin state of the nuclear spin. And resonant radiofrequency (RF) pulses are used to manipulate the nuclear spin states. (b) Four-level system composed by the NV electron spin and a strong coupled ¹³C nuclear spin. (c) Rabi oscillation of the ¹³C nuclear spin, pulse sequence in panel (a) is used.