title: Cavity QED with magnetically coupled collective spin states.
abstract: We report strong coupling between an ensemble of nitrogen-vacancy center electron spins in diamond and a superconducting microwave coplanar waveguide resonator. The characteristic scaling of the collective coupling strength with the square root of the number of emitters is observed directly. Additionally, we measure hyperfine coupling to (13)C nuclear spins, which is a first step towards a nuclear ensemble quantum memory. Using the dispersive shift of the cavity resonance frequency, we measure the relaxation time of the NV center at millikelvin temperatures in a nondestructive way.
authors: Vienna Center for Quantum Science and Technology, Atominstitut, TU Wien, Austria.
authors: R
authors: R
authors: Amsüss
authors: Ch
authors: Ch
authors: Koller
authors: T
authors: T
authors: Nöbauer
authors: S
authors: S
authors: Putz
authors: S
authors: S
authors: Rotter
authors: K
authors: K
authors: Sandner
authors: S
authors: S
authors: Schneider
authors: M
authors: M
authors: Schramböck
authors: G
authors: G
authors: Steinhauser
authors: H
authors: H
authors: Ritsch
authors: J
authors: J
authors: Schmiedmayer
authors: J
authors: J
authors: Majer