Nuclear spins in certain solids couple weakly to their environment, making them attractive candidates for quantum information processing and inertial sensing. When coupled to the spin of an optically active electron, nuclear spins can be rapidly polarized, controlled, and read via lasers and radio-frequency (rf) fields. Possessing typical coherence times of several milliseconds at room temperature, nuclear spins hosted by a nitrogen-vacancy center in diamond are thus intriguing systems to observe how classical physical rotation at quantum timescales affects a quantum system. In this work, we demonstrate optical nuclear-spin polarization and rapid quantum control of nuclear spins in a diamond physically rotating at $1\phantom{\rule{0.16em}{0ex}}\mathrm{kHz}$ , faster than the nuclear-spin coherence time. Free from the need to maintain strict field alignment, we are able to measure and control nuclear spins in the presence of a large, time-varying magnetic field that makes an angle of more than ${100}^{\ensuremath{\circ}}$ to the nitrogen-lattice vacancy axis. The field induces spin mixing between the electron and nuclear states of the qubits, decoupling them from oscillating rf fields. We are able to demonstrate that coherent spin state control is possible at any point of the rotation. We combine continuous dynamical decoupling with feed-forward control to eliminate decoherence induced by imperfect mechanical rotation. Our work liberates a previously inaccessible degree of freedom of the NV nuclear spin, unlocking new approaches to quantum control and rotation sensing.Nuclear spins in certain solids couple weakly to their environment, making them attractive candidates for quantum information processing and inertial sensing. When coupled to the spin of an optically active electron, nuclear spins can be rapidly polarized, controlled, and read via lasers and radio-frequency (rf) fields. Possessing typical coherence times of several milliseconds at room temperature, nuclear spins hosted by a nitrogen-vacancy center in diamond are thus intriguing systems to observe how classical physical rotation at quantum timescales affects a quantum system. In this work, we demonstrate optical nuclear-spin polarization and rapid quantum control of nuclear spins in a diamond physically rotating at $1\phantom{\rule{0.16em}{0ex}}\mathrm{kHz}$, faster than the nuclear-spin coherence time. Free from the need to maintain strict field alignment, we are able to measure and control nuclear spins in the presence of a large, time-varying magnetic field that makes an angle of more than ${100}^{\ensuremath{\circ}}$ to the nitrogen-lattice vacancy axis. The field induces spin mixing between the electron and nuclear states of the qubits, decoupling them from oscillating rf fields. We are able to demonstrate that coherent spin state control is possible at any point of the rotation. We combine continuous dynamical decoupling with feed-forward control to eliminate decoherence induced by imperfect mechanical rotation. Our work liberates a previously inaccessible degree of freedom of the NV nuclear spin, unlocking new approaches to quantum control and rotation sensing.

arXiv:2107.12577Physical Review ResearchDec 13, 202114 citations

Efficient nuclear spin–photon entanglement with optical routing

Javid Javadzade, Majid Zahedian, Florian Kaiser +2 more

Quantum networks and distributed quantum computing rely on entanglement generation between photons and long-lived stationary qubits. For large-scale architectures, one of the most crucial parameters is the efficiency at which entanglement can be created and detected. Here, we maximize the efficiency for the detection of hybrid entanglement between a nuclear spin qubit in diamond with a photonic time-bin qubit. Our approach relies on the optimal implementation of a photonic qubit analyzer, for which we use a high-speed electro-optical deflector to direct photons deterministically along the optimal interferometer paths. This way, we eliminate all cases in which photons are randomly lost due to propagation in the wrong interferometer path. We use nitrogen-vacancy centers in diamond, for which we demonstrate nuclear spin--photon entanglement with a fidelity of 0.6 reducing the experimental acquisition time by a factor of 2. An extension to other spin--photon entanglement systems and higher-dimensional entanglement schemes is outlined.Quantum networks and distributed quantum computing rely on entanglement generation between photons and long-lived stationary qubits. For large-scale architectures, one of the most crucial parameters is the efficiency at which entanglement can be created and detected. Here, we maximize the efficiency for the detection of hybrid entanglement between a nuclear spin qubit in diamond with a photonic time-bin qubit. Our approach relies on the optimal implementation of a photonic qubit analyzer, for which we use a high-speed electro-optical deflector to direct photons deterministically along the optimal interferometer paths. This way, we eliminate all cases in which photons are randomly lost due to propagation in the wrong interferometer path. We use nitrogen-vacancy centers in diamond, for which we demonstrate nuclear spin--photon entanglement with a fidelity of 0.6 reducing the experimental acquisition time by a factor of 2. An extension to other spin--photon entanglement systems and higher-dimensional entanglement schemes is outlined.

arXiv:2408.01824Physical Review AppliedJul 29, 20253 citations

Quantum measurement and control of rapidly rotating single qubits in diamond

A. A. Wood, Emmanuel Lilette, Yaakov Y. Fein +7 more

Bulletin of the American Physical SocietyJun 8, 20170 citations

Robust control of nuclear spins in diamond

Lilian Childress, Benjamin K. Smeltzer

Bulletin of the American Physical SocietyMay 27, 20100 citations

Robust control of individual nuclear spins in diamond

Benjamin K. Smeltzer, Jean McIntyre, Lilian Childress

Isolated nuclear spins provide a promising building block for quantum information science, motivating development of techniques to characterize, control, and detect them in suitable systems. Working with the nitrogen-vacancy center in diamond, we demonstrate robust initialization, manipulation, and readout of individual $^{13}\text{C}$ , $^{15}\text{N}$ , and $^{14}\text{N}$ nuclear spins and identify a mechanism to extend our results to arbitrary magnetic field environments. These techniques enable precise characterization of nuclear-spin hyperfine parameters and coherence properties and may pave the way for nuclear-spin-based quantum information architectures in diamond.Isolated nuclear spins provide a promising building block for quantum information science, motivating development of techniques to characterize, control, and detect them in suitable systems. Working with the nitrogen-vacancy center in diamond, we demonstrate robust initialization, manipulation, and readout of individual $^{13}\text{C}$, $^{15}\text{N}$, and $^{14}\text{N}$ nuclear spins and identify a mechanism to extend our results to arbitrary magnetic field environments. These techniques enable precise characterization of nuclear-spin hyperfine parameters and coherence properties and may pave the way for nuclear-spin-based quantum information architectures in diamond.

arXiv:0909.3896Physical Review ANov 25, 2009163 citations

1\phantom{\rule{0.16em}{0ex}}\mathrm{kHz}

, faster than the nuclear-spin coherence time. Free from the need to maintain strict field alignment, we are able to measure and control nuclear spins in the presence of a large, time-varying magnetic field that makes an angle of more than ${100}^{\ensuremath{\circ}}$ to the nitrogen-lattice vacancy axis. The field induces spin mixing between the electron and nuclear states of the qubits, decoupling them from oscillating rf fields. We are able to demonstrate that coherent spin state control is possible at any point of the rotation. We combine continuous dynamical decoupling with feed-forward control to eliminate decoherence induced by imperfect mechanical rotation. Our work liberates a previously inaccessible degree of freedom of the NV nuclear spin, unlocking new approaches to quantum control and rotation sensing.

^{13}\text{C}

^{15}\text{N}

, and

^{14}\text{N}

nuclear spins and identify a mechanism to extend our results to arbitrary magnetic field environments. These techniques enable precise characterization of nuclear-spin hyperfine parameters and coherence properties and may pave the way for nuclear-spin-based quantum information architectures in diamond.