title: Tuning a spin bath through the quantum-classical transition.
abstract: We study decoherence of a single nitrogen-vacancy (NV) center induced by the 13C nuclear spin bath of diamond. By comparing Hahn-Echo experiments on single and double-quantum transitions of the NV triplet ground state we demonstrate that this bath can be tuned into two different regimes. At low magnetic fields, the nuclei behave as a quantum bath which causes decoherence by entangling with the NV central spin. At high magnetic fields, the bath behaves as a source of classical magnetic field noise, which creates decoherence by imprinting a random phase on the NV central spin.
authors.affiliation: 3rd Physics Institute and Research Center SCoPE, University of Stuttgart, 70569 Stuttgart, Germany.
authors.forename: Friedemann
authors.initials: F
authors.lastname: Reinhard
authors.forename: Fazhan
authors.initials: F
authors.lastname: Shi
authors.forename: Nan
authors.initials: N
authors.lastname: Zhao
authors.forename: Florian
authors.initials: F
authors.lastname: Rempp
authors.forename: Boris
authors.initials: B
authors.lastname: Naydenov
authors.forename: Jan
authors.initials: J
authors.lastname: Meijer
authors.forename: Liam T
authors.initials: LT
authors.lastname: Hall
authors.forename: Lloyd
authors.initials: L
authors.lastname: Hollenberg
authors.forename: Jiangfeng
authors.initials: J
authors.lastname: Du
authors.forename: Ren-Bao
authors.initials: RB
authors.lastname: Liu
authors.forename: Jörg
authors.initials: J
authors.lastname: Wrachtrup