title: Quantum control of hybrid nuclear-electronic qubits.
abstract: Pulsed magnetic resonance allows the quantum state of electronic and nuclear spins to be controlled on the timescale of nanoseconds and microseconds respectively. The time required to flip dilute spins is orders of magnitude shorter than their coherence times, leading to several schemes for quantum information processing with spin qubits. Instead, we investigate 'hybrid nuclear-electronic' qubits consisting of near 50:50 superpositions of the electronic and nuclear spin states. Using bismuth-doped silicon, we demonstrate quantum control over these states in 32 ns, which is orders of magnitude faster than previous experiments using pure nuclear states. The coherence times of up to 4 ms are five orders of magnitude longer than the manipulation times, and are limited only by naturally occurring (29)Si nuclear spin impurities. We find a quantitative agreement between our experiments and an analytical theory for the resonance positions, as well as their relative intensities and Rabi oscillation frequencies. These results bring spins in a solid material a step closer to research on ion-trap qubits.
authors.affiliation: Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK. gavin.morley@warwick.ac.uk
authors.forename: Gavin W
authors.initials: GW
authors.lastname: Morley
authors.forename: Petra
authors.initials: P
authors.lastname: Lueders
authors.forename: M Hamed
authors.initials: MH
authors.lastname: Mohammady
authors.forename: Setrak J
authors.initials: SJ
authors.lastname: Balian
authors.forename: Gabriel
authors.initials: G
authors.lastname: Aeppli
authors.forename: Christopher W M
authors.initials: CW
authors.lastname: Kay
authors.forename: Wayne M
authors.initials: WM
authors.lastname: Witzel
authors.forename: Gunnar
authors.initials: G
authors.lastname: Jeschke
authors.forename: Tania S
authors.initials: TS
authors.lastname: Monteiro
mesh_terms: D001729:Bismuth / Q000737:chemistry; D004574:Electromagnetic Fields; D004579:Electron Transport; D004583:Electrons; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D008422:Materials Testing; D053758:Nanoparticles; D011789:Quantum Theory; D012815:Signal Processing, Computer-Assisted; D012825:Silicon / Q000737:chemistry
chemical_list: D001729:Bismuth; D012825:Silicon