High-fidelity projective readout of a solid-state spin quantum register

Abstract

Initialization and readout of coupled quantum systems are essential ingredients for the implementation of quantum algorithms. If the state of a multi-qubit register can be read out in a single shot, this enables further key resources such as quantum error correction and deterministic quantum teleportation, as well as direct investigation of quantum correlations (entanglement). While spins in solids are attractive candidates for scalable quantum information processing, thus far single-shot detection has only been achieved for isolated qubits. Here, we demonstrate preparation and measurement of a multi-spin quantum register by implementing resonant optical excitation techniques originally developed in atomic physics. We achieve high-fidelity readout of the electronic spin associated with a single nitrogen-vacancy (NV) centre in diamond at low temperature, and exploit this readout to project up to three nearby nuclear spin qubits onto a well-defined state. Conversely, we can distinguish the state of the nuclear spins in a single shot by mapping it onto and subsequently measuring the electronic spin. Finally, we show compatibility with qubit control by demonstrating initialization, coherent manipulation, and single-shot readout in a single experiment on a two-qubit register, using techniques suitable for extension to larger registers. These results pave the way for the first test of Bell's inequalities on solid-state spins and the implementation of measurement-based quantum information protocols.

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References in corpus (11)

• High-sensitivity diamond magnetometer with nanoscale resolution
• Single-shot read-out of an individual electron spin in a quantum dot
• Universal dynamical decoupling of a single solid-state spin from a spin bath
• Scanning magnetic field microscope with a diamond single-spin sensor
• Dynamic polarization of single nuclear spins by optical pumping of NV color centers in diamond at room temperature
• Extending Quantum Coherence in Diamond
• Strongly enhanced photon collection from diamond defect centres under micro-fabricated integrated solid immersion lenses
• Dynamical Decoupling of a single electron spin at room temperature
• Excited-state spectroscopy using single-spin manipulation in diamond
• A fast and robust approach to long-distance quantum communication with atomic ensembles
• Control and coherence of the optical transition of single defect centers in diamond

Cited by in corpus (11)

• Detection and control of individual nuclear spins using a weakly coupled electron spin
• Engineering shallow spins in diamond with nitrogen delta-doping
• Low Temperature Studies of Charge Dynamics of Nitrogen-Vacancy Defect in Diamond
• Demonstration of entanglement-by-measurement of solid state qubits
• Initialization by measurement of a two-qubit superconducting circuit
• Opening up the Quantum Three-Box Problem with Undetectable Measurements
• Preservation of quantum correlation between separated nitrogen-vacancy centers embedded in photonic crystal cavities
• Room-temperature high-speed nuclear-spin quantum memory in diamond
• Measuring mechanical motion with a single spin
• Collectively Enhanced Interactions in Solid-state Spin Qubits
• Spin bath narrowing with adaptive parameter estimation