title: Subnanometre resolution in three-dimensional magnetic resonance imaging of individual dark spins.
abstract: Magnetic resonance imaging (MRI) has revolutionized biomedical science by providing non-invasive, three-dimensional biological imaging. However, spatial resolution in conventional MRI systems is limited to tens of micrometres, which is insufficient for imaging on molecular scales. Here, we demonstrate an MRI technique that provides subnanometre spatial resolution in three dimensions, with single electron-spin sensitivity. Our imaging method works under ambient conditions and can measure ubiquitous 'dark' spins, which constitute nearly all spin targets of interest. In this technique, the magnetic quantum-projection noise of dark spins is measured using a single nitrogen-vacancy (NV) magnetometer located near the surface of a diamond chip. The distribution of spins surrounding the NV magnetometer is imaged with a scanning magnetic-field gradient. To evaluate the performance of the NV-MRI technique, we image the three-dimensional landscape of electronic spins at the diamond surface and achieve an unprecedented combination of resolution (0.8 nm laterally and 1.5 nm vertically) and single-spin sensitivity. Our measurements uncover electronic spins on the diamond surface that can potentially be used as resources for improved magnetic imaging. This NV-MRI technique is immediately applicable to diverse systems including imaging spin chains, readout of spin-based quantum bits, and determining the location of spin labels in biological systems.
authors.affiliation: Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: M S
authors.initials: MS
authors.lastname: Grinolds
authors.affiliation: Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: M
authors.initials: M
authors.lastname: Warner
authors.affiliation: Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: K
authors.initials: K
authors.lastname: De Greve
authors.affiliation: Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: Y
authors.initials: Y
authors.lastname: Dovzhenko
authors.affiliation: 1] Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA [2] Department of Physics, University of Basel, Klingelbergstrasse 82, Basel, CH-4056 Switzerland.
authors.forename: L
authors.initials: L
authors.lastname: Thiel
authors.affiliation: 1] Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA [2] Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, Massachusetts 02138, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Walsworth
authors.affiliation: Vienna Center for Quantum Science and Technology (VCQ), Faculty of Physics, University of Vienna, Boltzmanngasse 5, A-1090 Vienna, Austria.
authors.forename: S
authors.initials: S
authors.lastname: Hong
authors.affiliation: Department of Physics, University of Basel, Klingelbergstrasse 82, Basel, CH-4056 Switzerland.
authors.forename: P
authors.initials: P
authors.lastname: Maletinsky
authors.affiliation: Department of Physics, Harvard University, 17 Oxford Street, Cambridge, Massachusetts 02138, USA.
authors.forename: A
authors.initials: A
authors.lastname: Yacoby
mesh_terms: D018130:Diamond / Q000737:chemistry; D008279:Magnetic Resonance Imaging / Q000295:instrumentation / Q000379:methods*; D008962:Models, Theoretical; D012680:Sensitivity and Specificity; D013113:Spin Labels
chemical_list: D013113:Spin Labels; D018130:Diamond