Nitrogen-vacancy （NV） center in diamond is one of the most promising candidates to implement room temperature quantum computing. In this review, we briefly discuss the working principles and recent experimental prog...Nitrogen-vacancy （NV） center in diamond is one of the most promising candidates to implement room temperature quantum computing. In this review, we briefly discuss the working principles and recent experimental progresses of this spin qubit. These results focus on understanding and prolonging center spin coherence, steering and probing spin states with dedicated quantum control techniques, and exploiting the quantum nature of these multi-spin systems, such as superposition and entanglement, to demonstrate the superiority of quantum information processing. Those techniques also stimulate the fast development of NV-based quantum sensing, which is an interdisciplinary field with great potential applications.展开更多
The diamond anvil cell-based high-pressure technique is a unique tool for creating new states of matter and for understanding the physics underlying some exotic phenomena.In situ sensing of spin and charge properties ...The diamond anvil cell-based high-pressure technique is a unique tool for creating new states of matter and for understanding the physics underlying some exotic phenomena.In situ sensing of spin and charge properties under high pressure is crucially important but remains technically challenging.While the nitrogen-vacancy(NV)center in diamond is a promising quantum sensor under extreme conditions,its spin dynamics and the quantum control of its spin states under high pressure remain elusive.In this study,we demonstrate coherent control,spin relaxation,and spin dephasing measurements for ensemble NV centers up to 32.8 GPa.With this in situ quantum sensor,we investigate the pressure-induced magnetic phase transition of a micron-size permanent magnet Nd2Fe14B sample in a diamond anvil cell,with a spatial resolution of ~2μm,and sensitivity of ~20 μT/Hz1/2. This scheme could be generalized to measure other parameters such as temperature,pressure and their gradients under extreme conditions.This will be beneficial for frontier research of condensed matter physics and geophysics.展开更多
Controlled manipulation of the electron spin by means of a microwave field is investigated. The near magnetic field generated by a copper wire antenna is measured experimentally and simulated theoretically, and the op...Controlled manipulation of the electron spin by means of a microwave field is investigated. The near magnetic field generated by a copper wire antenna is measured experimentally and simulated theoretically, and the optimum antenna length and position are obtained. By measuring the change in the fluorescence of nitrogen-vacancy （N-V） centers in diamond after excitation with a 532 nm continuous wave laser at room temperature, it is verified that the spin of the N-V center can be effectively controlled by the microwave field.展开更多
We investigate the Ramsey fringes of a single electron spin of the nitrogen-vacancy center in diamond with different microwave radiation frequency detunings.The fast Fourier transform demonstrates that the Ramsey frin...We investigate the Ramsey fringes of a single electron spin of the nitrogen-vacancy center in diamond with different microwave radiation frequency detunings.The fast Fourier transform demonstrates that the Ramsey fringes consist of three components caused by hyperfine interaction with 14N nuclear spin,and the Ramsey fringes cannot be well explained without the phase term of the three components,which has not been mentioned before.Each phase is determined by the microwave frequency detuning and the resonant Rabi frequency as well as the π/2 pulse.展开更多
We present the experimental results of nitrogen-vacancy （NV） electron spin decoherence, which are linked to the coexistence of electron spin bath of nitrogen impurity （PI center） and 13C nuclear spin bath. In prev...We present the experimental results of nitrogen-vacancy （NV） electron spin decoherence, which are linked to the coexistence of electron spin bath of nitrogen impurity （PI center） and 13C nuclear spin bath. In previous works, only one dominant decoherence source is studied： P1 electron spin bath for type-Ⅰb diamond; or 13C nuclear spin bath for type-Ⅱa diamond. In general, the thermal fluctuation from both spin baths can be eliminated by the Hahn echo sequence, resulting in a long coherence time （T2 ） of about 400#8. However, in a high-purity type-Ⅱa diamond where 1℃ nuclear spin bath is the dominant decoherence source, dramatic decreases of NV electron spin T2 time caused by P1 electron spin bath are observed under certain magnetic field. We further apply the engineered Hahn echo sequence to confirm the decoherenee mechanism of multiple spin baths and quantitatively estimate the contribution of P1 electron spin bath. Our results are helpful to understand the NV decoherence mechanisms, which will benefit quantum computing and quantum metrology.展开更多
This work⑴was additionally supported by the National Key R&D Program of China under Grant No 2018YFA0305700.The financial acknowledgment section should be corrected as follows:Supported by the National Basic Rese...This work⑴was additionally supported by the National Key R&D Program of China under Grant No 2018YFA0305700.The financial acknowledgment section should be corrected as follows:Supported by the National Basic Research Program of China under Grant No 2015CB921103,the National Key R&D Program of China under Grant Nos 2016YFA0401503 and 2018YFA0305700,the Strategic Priority Research Program of Chinese Academy of Sciences under Grant No XDB28000000.展开更多
基金Project supported by the National Basic Research Program of China(Grant Nos.2014CB921402 and 2015CB921103)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB07010300)+1 种基金the National Natural Science Foundation of China(Grant No.11574386)the Key Research Program of the Chinese Academy of Sciences(Grant No.XDPB0803)
文摘Nitrogen-vacancy （NV） center in diamond is one of the most promising candidates to implement room temperature quantum computing. In this review, we briefly discuss the working principles and recent experimental progresses of this spin qubit. These results focus on understanding and prolonging center spin coherence, steering and probing spin states with dedicated quantum control techniques, and exploiting the quantum nature of these multi-spin systems, such as superposition and entanglement, to demonstrate the superiority of quantum information processing. Those techniques also stimulate the fast development of NV-based quantum sensing, which is an interdisciplinary field with great potential applications.
基金Supported by the National Basic Research Program of China under Grant No 2015CB921103the National Key R&D Program of China under Grant No 2016YFA0401503+2 种基金the Strategic Priority Research Program of Chinese Academy of Sciences under Grant No XDB28000000the National Natural Science Foundation of China under Grant Nos 11574386,11575288 and 51402350the Youth Innovation Promotion Association of Chinese Academy of Sciences under Grant No 2016006
文摘The diamond anvil cell-based high-pressure technique is a unique tool for creating new states of matter and for understanding the physics underlying some exotic phenomena.In situ sensing of spin and charge properties under high pressure is crucially important but remains technically challenging.While the nitrogen-vacancy(NV)center in diamond is a promising quantum sensor under extreme conditions,its spin dynamics and the quantum control of its spin states under high pressure remain elusive.In this study,we demonstrate coherent control,spin relaxation,and spin dephasing measurements for ensemble NV centers up to 32.8 GPa.With this in situ quantum sensor,we investigate the pressure-induced magnetic phase transition of a micron-size permanent magnet Nd2Fe14B sample in a diamond anvil cell,with a spatial resolution of ~2μm,and sensitivity of ~20 μT/Hz1/2. This scheme could be generalized to measure other parameters such as temperature,pressure and their gradients under extreme conditions.This will be beneficial for frontier research of condensed matter physics and geophysics.
文摘Controlled manipulation of the electron spin by means of a microwave field is investigated. The near magnetic field generated by a copper wire antenna is measured experimentally and simulated theoretically, and the optimum antenna length and position are obtained. By measuring the change in the fluorescence of nitrogen-vacancy （N-V） centers in diamond after excitation with a 532 nm continuous wave laser at room temperature, it is verified that the spin of the N-V center can be effectively controlled by the microwave field.
基金Supported by the National Basic Research Program of China under Grant No 2009CB929103the National Natural Science Foundation of China under Grant No 10974251.
文摘We investigate the Ramsey fringes of a single electron spin of the nitrogen-vacancy center in diamond with different microwave radiation frequency detunings.The fast Fourier transform demonstrates that the Ramsey fringes consist of three components caused by hyperfine interaction with 14N nuclear spin,and the Ramsey fringes cannot be well explained without the phase term of the three components,which has not been mentioned before.Each phase is determined by the microwave frequency detuning and the resonant Rabi frequency as well as the π/2 pulse.
基金Supported by the National Basic Research Program of China under Grant Nos 2014CB921402 and 2015CB921103the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDB07010300the National Natural Science Foundation of China under Grant No 11574386
文摘We present the experimental results of nitrogen-vacancy （NV） electron spin decoherence, which are linked to the coexistence of electron spin bath of nitrogen impurity （PI center） and 13C nuclear spin bath. In previous works, only one dominant decoherence source is studied： P1 electron spin bath for type-Ⅰb diamond; or 13C nuclear spin bath for type-Ⅱa diamond. In general, the thermal fluctuation from both spin baths can be eliminated by the Hahn echo sequence, resulting in a long coherence time （T2 ） of about 400#8. However, in a high-purity type-Ⅱa diamond where 1℃ nuclear spin bath is the dominant decoherence source, dramatic decreases of NV electron spin T2 time caused by P1 electron spin bath are observed under certain magnetic field. We further apply the engineered Hahn echo sequence to confirm the decoherenee mechanism of multiple spin baths and quantitatively estimate the contribution of P1 electron spin bath. Our results are helpful to understand the NV decoherence mechanisms, which will benefit quantum computing and quantum metrology.
文摘This work⑴was additionally supported by the National Key R&D Program of China under Grant No 2018YFA0305700.The financial acknowledgment section should be corrected as follows:Supported by the National Basic Research Program of China under Grant No 2015CB921103,the National Key R&D Program of China under Grant Nos 2016YFA0401503 and 2018YFA0305700,the Strategic Priority Research Program of Chinese Academy of Sciences under Grant No XDB28000000.
