title: Quantum Metrology Enhanced by Repetitive Quantum Error Correction.
abstract: We experimentally demonstrate the protection of a room-temperature hybrid spin register against environmental decoherence by performing repeated quantum error correction whilst maintaining sensitivity to signal fields. We use a long-lived nuclear spin to correct multiple phase errors on a sensitive electron spin in diamond and realize magnetic field sensing beyond the time scales set by natural decoherence. The universal extension of sensing time, robust to noise at any frequency, demonstrates the definitive advantage entangled multiqubit systems provide for quantum sensing and offers an important complement to quantum control techniques.
authors.affiliation: Institute of Quantum Optics, Ulm University, 89081 Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Unden
authors.affiliation: Institute of Quantum Optics, Ulm University, 89081 Ulm, Germany.
authors.forename: Priya
authors.initials: P
authors.lastname: Balasubramanian
authors.affiliation: Institute of Quantum Optics, Ulm University, 89081 Ulm, Germany.|Racah Institute of Physics, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
authors.forename: Daniel
authors.initials: D
authors.lastname: Louzon
authors.affiliation: Racah Institute of Physics, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
authors.forename: Yuval
authors.initials: Y
authors.lastname: Vinkler
authors.affiliation: Center for Integrated Quantum Science and Technology (IQST), Ulm University, 89081 Ulm, Germany.|Institute for Theoretical Physics, Ulm University, 89081 Ulm, Germany.
authors.forename: Martin B
authors.initials: MB
authors.lastname: Plenio
authors.affiliation: Element Six, Harwell Campus, Fermi Avenue, Didcot OX11 0QR, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Markham
authors.affiliation: Element Six, Harwell Campus, Fermi Avenue, Didcot OX11 0QR, United Kingdom.
authors.forename: Daniel
authors.initials: D
authors.lastname: Twitchen
authors.affiliation: Element Six, Harwell Campus, Fermi Avenue, Didcot OX11 0QR, United Kingdom.
authors.forename: Alastair
authors.initials: A
authors.lastname: Stacey
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Igor
authors.initials: I
authors.lastname: Lovchinsky
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Alexander O
authors.initials: AO
authors.lastname: Sushkov
authors.affiliation: Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA.
authors.forename: Mikhail D
authors.initials: MD
authors.lastname: Lukin
authors.affiliation: Racah Institute of Physics, Hebrew University of Jerusalem, 91904 Jerusalem, Israel.
authors.forename: Alex
authors.initials: A
authors.lastname: Retzker
authors.affiliation: Institute of Quantum Optics, Ulm University, 89081 Ulm, Germany.|Center for Integrated Quantum Science and Technology (IQST), Ulm University, 89081 Ulm, Germany.
authors.forename: Boris
authors.initials: B
authors.lastname: Naydenov
authors.affiliation: Institute of Quantum Optics, Ulm University, 89081 Ulm, Germany.
authors.forename: Liam P
authors.initials: LP
authors.lastname: McGuinness
authors.affiliation: Institute of Quantum Optics, Ulm University, 89081 Ulm, Germany.|Center for Integrated Quantum Science and Technology (IQST), Ulm University, 89081 Ulm, Germany.
authors.forename: Fedor
authors.initials: F
authors.lastname: Jelezko