Single-Shot Readout of a Nuclear Spin Weakly Coupled to a Nitrogen-Vacancy Center at Room Temperature.

Single-shot readout of qubits is required for scalable quantum computing. Nuclear spins are superb quantum memories due to their long coherence time, but are difficult to be read out in a single shot due to their weak interaction with probes. Here we demonstrate single-shot readout of a weakly coupled ^{13}C nuclear spin at room temperature, which is unresolvable in traditional protocols. States of the weakly coupled nuclear spin are trapped and read out projectively by sequential weak measurements, which are implemented by dynamical decoupling pulses. A nuclear spin coupled to the nitrogen-vacancy (NV) center with strength 330 kHz is read out in 200 ms with a fidelity of 95.5%. This work provides a general protocol for single-shot readout of weakly coupled qubits at room temperature and therefore largely extends the range of physical systems for scalable quantum computing.

[1]  J. Wrachtrup,et al.  Multipartite Entanglement Among Single Spins in Diamond , 2008, Science.

[2]  Matthias Steiner,et al.  Single-Shot Readout of a Single Nuclear Spin , 2010, Science.

[3]  Ren-Bao Liu,et al.  Angstrom-Resolution Magnetic Resonance Imaging of Single Molecules via Wave-Function Fingerprints of Nuclear Spins , 2015, 1510.04081.

[4]  F. Jelezko,et al.  Dark states of single nitrogen-vacancy centers in diamond unraveled by single shot NMR. , 2010, Physical review letters.

[5]  N. Zhao,et al.  Atomic-scale magnetometry of distant nuclear spin clusters via nitrogen-vacancy spin in diamond. , 2010, Nature nanotechnology.

[6]  Eugene E. Haller,et al.  Solid-state quantum memory using the 31P nuclear spin , 2008, Nature.

[7]  Y. Wang,et al.  Quantum error correction in a solid-state hybrid spin register , 2013, Nature.

[8]  Jiangfeng Du,et al.  Sensing and atomic-scale structure analysis of single nuclear-spin clusters in diamond , 2013, Nature Physics.

[9]  C. Macklin,et al.  Observing single quantum trajectories of a superconducting quantum bit , 2013, Nature.

[10]  Wen Yang,et al.  Preserving qubit coherence by dynamical decoupling , 2010, 1007.0623.

[11]  Wen Yang,et al.  Theory of nuclear spin dephasing and relaxation by optically illuminated nitrogen-vacancy center , 2015, 1507.06385.

[12]  M. Markham,et al.  Demonstration of entanglement-by-measurement of solid-state qubits , 2012, Nature Physics.

[13]  D. DiVincenzo,et al.  The Physical Implementation of Quantum Computation , 2000, quant-ph/0002077.

[14]  Andrew S. Dzurak,et al.  High-fidelity readout and control of a nuclear spin qubit in silicon , 2013, Nature.

[15]  R Hanson,et al.  Universal control and error correction in multi-qubit spin registers in diamond. , 2013, Nature nanotechnology.

[16]  M. Markham,et al.  High-fidelity transfer and storage of photon states in a single nuclear spin , 2015, Nature Photonics.

[17]  J. Cirac,et al.  Room-Temperature Quantum Bit Memory Exceeding One Second , 2012, Science.

[18]  M. Plenio,et al.  Filter design for hybrid spin gates , 2015, 1504.03575.

[19]  A. Jordan,et al.  Mapping the optimal route between two quantum states , 2014, Nature.

[20]  D. J. Twitchen,et al.  Manipulating a qubit through the backaction of sequential partial measurements and real-time feedback , 2013, Nature Physics.

[21]  Neil B. Manson,et al.  The negatively charged nitrogen-vacancy centre in diamond: the electronic solution , 2010, 1008.5224.

[22]  Wang Yao,et al.  Quantum computing by optical control of electron spins , 2010, 1006.5544.

[23]  B. E. Kane.  A silicon-based nuclear spin quantum computer , 1998, Nature.

[24]  Vaidman,et al.  How the result of a measurement of a component of the spin of a spin-1/2 particle can turn out to be 100. , 1988, Physical review letters.

[25]  Jiangfeng Du,et al.  Noise-resilient quantum evolution steered by dynamical decoupling , 2013, Nature Communications.

[26]  N. Kalb,et al.  Experimental creation of quantum Zeno subspaces by repeated multi-spin projections in diamond , 2016, Nature Communications.

[27]  J R Maze,et al.  Single-shot readout of multiple nuclear spin qubits in diamond under ambient conditions. , 2012, Physical review letters.

[28]  Ren-Bao Liu,et al.  Controllable effects of quantum fluctuations on spin free-induction decay at room temperature , 2011, Scientific Reports.

[29]  J. S. Hodges,et al.  Repetitive Readout of a Single Electronic Spin via Quantum Logic with Nuclear Spin Ancillae , 2009, Science.

[30]  L. Childress,et al.  Supporting Online Material for , 2006 .

[31]  B. Hensen,et al.  High-fidelity projective read-out of a solid-state spin quantum register , 2011, Nature.

[32]  Nan Zhao,et al.  Sensing single remote nuclear spins. , 2012, Nature nanotechnology.

[33]  S. Bennett,et al.  Sensing distant nuclear spins with a single electron spin. , 2012, Physical review letters.

[34]  F. Jelezko,et al.  Observation of coherent oscillation of a single nuclear spin and realization of a two-qubit conditional quantum gate. , 2004, Physical review letters.

[35]  M. A. Rol,et al.  Repeated quantum error correction on a continuously encoded qubit by real-time feedback , 2015, Nature Communications.

[36]  T. Taminiau,et al.  Detection and control of individual nuclear spins using a weakly coupled electron spin. , 2012, Physical review letters.

[37]  Norbert Kalb,et al.  Robust quantum-network memory using decoherence-protected subspaces of nuclear spins , 2016, 1603.01602.

[38]  J. M. Taylor,et al.  Electron spin decoherence of single nitrogen-vacancy defects in diamond , 2008, 0805.0327.

[39]  N. Zhao,et al.  Decoherence and dynamical decoupling control of nitrogen vacancy center electron spins in nuclear spin baths , 2011, 1108.2343.

[40]  P Cappellaro,et al.  Coherence of an optically illuminated single nuclear spin qubit. , 2007, Physical review letters.