title: Optically detected cross-relaxation spectroscopy of electron spins in diamond.
abstract: The application of magnetic resonance spectroscopy at progressively smaller length scales may eventually permit 'chemical imaging' of spins at the surfaces of materials and biological complexes. In particular, the negatively charged nitrogen-vacancy (NV(-)) centre in diamond has been exploited as an optical transducer for nanoscale nuclear magnetic resonance. However, the spectra of detected spins are generally broadened by their interaction with proximate paramagnetic NV(-) centres through coherent and incoherent mechanisms. Here we demonstrate a detection technique that can resolve the spectra of electron spins coupled to NV(-) centres, in this case, substitutional nitrogen and neutral nitrogen-vacancy centres in diamond, through optically detected cross-relaxation. The hyperfine spectra of these spins are a unique chemical identifier, suggesting the possibility, in combination with recent results in diamonds harbouring shallow NV(-) implants, that the spectra of spins external to the diamond can be similarly detected.
authors.affiliation: 1] Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA [2] Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.
authors.forename: Hai-Jing
authors.initials: HJ
authors.lastname: Wang
authors.affiliation: 1] Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA [2] Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.
authors.forename: Chang S
authors.initials: CS
authors.lastname: Shin
authors.affiliation: 1] Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA [2] Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Seltzer
authors.affiliation: 1] Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA [2] Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Avalos
authors.affiliation: 1] Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA [2] Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.
authors.forename: Alexander
authors.initials: A
authors.lastname: Pines
authors.affiliation: 1] Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720, USA [2] Department of Chemistry and California Institute for Quantitative Biosciences, University of California, Berkeley, California 94720, USA.
authors.forename: Vikram S
authors.initials: VS
authors.lastname: Bajaj