title: Local and bulk (13)C hyperpolarization in nitrogen-vacancy-centred diamonds at variable fields and orientations.
abstract: Polarizing nuclear spins is of fundamental importance in biology, chemistry and physics. Methods for hyperpolarizing (13)C nuclei from free electrons in bulk usually demand operation at cryogenic temperatures. Room temperature approaches targeting diamonds with nitrogen-vacancy centres could alleviate this need; however, hitherto proposed strategies lack generality as they demand stringent conditions on the strength and/or alignment of the magnetic field. We report here an approach for achieving efficient electron-(13)C spin-alignment transfers, compatible with a broad range of magnetic field strengths and field orientations with respect to the diamond crystal. This versatility results from combining coherent microwave- and incoherent laser-induced transitions between selected energy states of the coupled electron-nuclear spin manifold. (13)C-detected nuclear magnetic resonance experiments demonstrate that this hyperpolarization can be transferred via first-shell or via distant (13)Cs throughout the nuclear bulk ensemble. This method opens new perspectives for applications of diamond nitrogen-vacancy centres in nuclear magnetic resonance, and in quantum information processing.
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Gonzalo A
authors.initials: GA
authors.lastname: Álvarez
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Christian O
authors.initials: CO
authors.lastname: Bretschneider
authors.affiliation: Department of Physics, Technion, Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Ran
authors.initials: R
authors.lastname: Fischer
authors.affiliation: Department of Physics, Technion, Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: Paz
authors.initials: P
authors.lastname: London
authors.affiliation: National Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044, Japan.
authors.forename: Hisao
authors.initials: H
authors.lastname: Kanda
authors.affiliation: Japan Atomic Energy Agency, 1233 Watanuki, Takasaki, Gunma 370-1292, Japan.
authors.forename: Shinobu
authors.initials: S
authors.lastname: Onoda
authors.affiliation: Research Center for Knowledge Communities, University of Tsukuba, 1-2 Kasuga, Tsukuba, Ibaraki 305-8550, Japan.
authors.forename: Junichi
authors.identifier: http://orcid.org/0000-0002-9598-625X
authors.initials: J
authors.lastname: Isoya
authors.affiliation: Department of Physics, Technion, Israel Institute of Technology, Haifa 32000, Israel.
authors.forename: David
authors.initials: D
authors.lastname: Gershoni
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel.
authors.forename: Lucio
authors.initials: L
authors.lastname: Frydman