title: Inductive measurement of optically hyperpolarized phosphorous donor nuclei in an isotopically enriched silicon-28 crystal.
abstract: We experimentally demonstrate the first inductive readout of optically hyperpolarized phosphorus-31 donor nuclear spins in an isotopically enriched silicon-28 crystal. The concentration of phosphorus donors in the crystal was 1.5×10(15)  cm(-3), 3 orders of magnitude lower than has previously been detected via direct inductive detection. The signal-to-noise ratio measured in a single free induction decay from a 1  cm(3) sample (≈10(15) spins) was 113. By transferring the sample to an X-band ESR spectrometer, we were able to obtain a lower bound for the nuclear spin polarization at 1.7 K of ∼64%. The (31)P-T2 measured with a Hahn echo sequence was 420 ms at 1.7 K, which was extended to 1.2 s with a Carr Purcell cycle. The T1 of the (31)P nuclear spins at 1.7 K is extremely long and could not be determined, as no decay was observed even on a time scale of 4.5 h. Optical excitation was performed with a 1047 nm laser, which provided above-band-gap excitation of the silicon. The buildup of the hyperpolarization at 4.2 K followed a single exponential with a characteristic time of 577 s, while the buildup at 1.7 K showed biexponential behavior with characteristic time constants of 578 and 5670 s.
authors.affiliation: Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: P
authors.initials: P
authors.lastname: Gumann
authors.affiliation: Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Patange
authors.affiliation: Department of Physics and Astronomy, Wilder Laboratory, Dartmouth College, Hanover, New Hampshire 03755, USA.
authors.forename: C
authors.initials: C
authors.lastname: Ramanathan
authors.affiliation: Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: H
authors.initials: H
authors.lastname: Haas
authors.affiliation: Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.
authors.forename: O
authors.initials: O
authors.lastname: Moussa
authors.affiliation: Department of Physics, Simon Fraser University, Burnaby, British Columbia V5A 1S6, Canada.
authors.forename: M L W
authors.initials: ML
authors.lastname: Thewalt
authors.affiliation: Leibniz-Institut fuer Kristallzuechtung, 12489 Berlin, Germany.
authors.forename: H
authors.initials: H
authors.lastname: Riemann
authors.affiliation: Leibniz-Institut fuer Kristallzuechtung, 12489 Berlin, Germany.
authors.forename: N V
authors.initials: NV
authors.lastname: Abrosimov
authors.affiliation: PTB Braunschweig, 38116 Braunschweig, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Becker
authors.affiliation: VITCON Projectconsult GmbH, 07743 Jena, Germany.
authors.forename: H-J
authors.initials: HJ
authors.lastname: Pohl
authors.affiliation: School of Fundamental Science and Technology, Keio University, Yokohama, 3-14-1 Hiyoshi 223-8522, Japan.
authors.forename: K M
authors.initials: KM
authors.lastname: Itoh
authors.affiliation: Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Department of Physics and Astronomy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Waterloo Institute for Nanotechnology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada and Department of Chemistry, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada and Perimeter Institute for Theoretical Physics, Waterloo, Ontario N2L 2Y5, Canada.
authors.forename: D G
authors.initials: DG
authors.lastname: Cory