Control of Spin Coherence and Quantum Sensing in Diamond

Satoshi Kobayashi, Yuichiro Matsuzaki, Hiroki Morishita +4 more

The extension of spin coherence times is a crucial issue for quantum information and quantum sensing. In solid-state systems, suppressing noise through various techniques has been demonstrated. On the other hand, an electrical control for suppression is important toward individual controls of on-chip quantum-information devices. Here, we show electrical control for extension of the spin coherence times of 40-nm-deep ion-implanted single-nitrogen-vacancy center spins in diamond by suppressing magnetic noise. We apply 120 V dc across two contacts spaced by 10 \ensuremath{\mu}m. The spin coherence times, estimated from a free-induction decay and a Hahn-echo decay, are increased up to about 10 times (reaching 10 \ensuremath{\mu}s) and 1.4 times (reaching 150 \ensuremath{\mu}s), respectively. From the quantitative analysis, the dominant decoherence source, depending on the applied static electric field, is elucidated. Electrical control for extension can deliver a sensitivity enhancement to the dc sensing of temperature, pressure, and electric (but not magnetic) fields, opening up an alternative technique in solid-state quantum-information devices.

V. V. Dobrovitski

Satoshi Kobayashi, Yuichiro Matsuzaki, Hiroki Morishita +4 more

The extension of the spin coherence times is a crucial issue for quantum information and quantum sensing. In solid state systems, suppressing noises with various techniques have been demonstrated. On the other hand, an electrical control for suppression is important toward individual controls of on-chip quantum information devices. Here we show the electrical control for extension of the spin coherence times of 40 nm-deep ion-implanted single nitrogen vacancy center spins in diamond by suppressing magnetic noises. We applied 120 V DC across two contacts spaced by 10 micrometers. The spin coherence times, estimated from a free-induction-decay and a Hahn-echo decay, were increased up to about 10 times (reaching 10 microseconds) and 1.4 times (reaching 150 microseconds), respectively. From the quantitative analysis, the dominant decoherence source depending on the applied static electric field was elucidated. The electrical control for extension can deliver a sensitivity enhancement to the DC sensing of temperature, pressure and electric (but not magnetic) fields, opening a new technique in solid-state quantum information devices.

D.M. Toyli

Bob B. Buckley

Gang‐Qin Liu, Xing Jian, Xinyu Pan

Quantum computing and quantum sensing have received much attention in recent years. As an atomic quantum system with super-long coherence time and spin-dependent optical transitions at room temperature, nitrogen-vacancy (NV) center in diamond is one of the well-studied physical systems in quantum information science. In this review, we brief the working principles and quantum control techniques of this single spin system, and also several experimental demonstrations. We focus on the following points:1) coherent manipulation of single spins with optically detected magnetic resonance; 2) main mechanism of NV election spin decoherence and schemes of coherence protection; 3) quantum sensing and quantum computing applications of spin quantum control techniques. Some open questions are discussed at the end of this review.