title: Fast room-temperature phase gate on a single nuclear spin in diamond.
abstract: Nuclear spins support long lived quantum coherence due to weak coupling to the environment, but are difficult to rapidly control using nuclear magnetic resonance as a result of the small nuclear magnetic moment. We demonstrate a fast ∼500  ns nuclear spin phase gate on a (14)N nuclear spin qubit intrinsic to a nitrogen-vacancy center in diamond. The phase gate is enabled by the hyperfine interaction and off-resonance driving of electron spin transitions. Repeated applications of the phase gate bang-bang decouple the nuclear spin from the environment, locking the spin state for up to ∼140  μs.
authors: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors: S
authors: S
authors: Sangtawesin
authors: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors: T O
authors: TO
authors: Brundage
authors: Department of Physics, Princeton University, Princeton, New Jersey 08544, USA.
authors: J R
authors: JR
authors: Petta