title: Negatively charged nitrogen-vacancy centers in a 5 nm thin 12C diamond film.
abstract: We report successful introduction of negatively charged nitrogen-vacancy (NV(-)) centers in a 5 nm thin, isotopically enriched ([(12)C] = 99.99%) diamond layer by CVD. The present method allows for the formation of NV(-) in such a thin layer even when the surface is terminated by hydrogen atoms. NV(-) centers are found to have spin coherence times of between T2 ~ 10-100 μs at room temperature. Changing the surface termination to oxygen or fluorine leads to a slight increase in the NV(-) density, but not to any significant change in T2. The minimum detectable magnetic field estimated by this T2 is 3 nT after 100 s of averaging, which would be sufficient for the detection of nuclear magnetic fields exerted by a single proton. We demonstrate the suitability for nanoscale NMR by measuring the fluctuating field from ~10(4) proton nuclei placed on top of the 5 nm diamond film.
authors.affiliation: School of Fundamental Science and Technology, Keio University , Yokohama 223-8522, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Ohashi
authors.forename: T
authors.initials: T
authors.lastname: Rosskopf
authors.forename: H
authors.initials: H
authors.lastname: Watanabe
authors.forename: M
authors.initials: M
authors.lastname: Loretz
authors.forename: Y
authors.initials: Y
authors.lastname: Tao
authors.forename: R
authors.initials: R
authors.lastname: Hauert
authors.forename: S
authors.initials: S
authors.lastname: Tomizawa
authors.forename: T
authors.initials: T
authors.lastname: Ishikawa
authors.forename: J
authors.initials: J
authors.lastname: Ishi-Hayase
authors.forename: S
authors.initials: S
authors.lastname: Shikata
authors.forename: C L
authors.initials: CL
authors.lastname: Degen
authors.forename: K M
authors.initials: KM
authors.lastname: Itoh