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
We investigate spontaneous emission properties and control of the zero phonon line （ZPL） from a diamond nitrogen- vacancy （NV） center coherently driven by a single ellipfically polarized control field. We use the ...We investigate spontaneous emission properties and control of the zero phonon line （ZPL） from a diamond nitrogen- vacancy （NV） center coherently driven by a single ellipfically polarized control field. We use the Schrrdinger equation to calculate the probability amplitudes of the wave function of the coupled system and derive analytical expressions of the spontaneous emission spectra. The numerical results show that a few interesting phenomena such as enhancement, narrowing, suppression, and quenching of the ZPL spontaneous emission can be realized by modulating the polarization- dependent phase, the Zeeman shift, and the intensity of the control field in our system. In the dressed-state picture of the control field, we find that multiple spontaneously generated coherence arises due to three close-lying states decaying to the same state. These results are useful in real experiments.展开更多
Implementation of a nonlocal multi-qubit conditional phase gate is an essential requirement in some quantum infor- mation processing （QIP） tasks. Recently, a novel solid-state cavity quantum electrodynamics （QED） ...Implementation of a nonlocal multi-qubit conditional phase gate is an essential requirement in some quantum infor- mation processing （QIP） tasks. Recently, a novel solid-state cavity quantum electrodynamics （QED） system, in which the nitrogen-vacancy （NV） center in diamond is coupled to a microtoroidal resonator （MTR）, has been proposed as a poten- tial system for hybrid quantum information and computing. By virtue of such systems, we present a scheme to realize a nonlocal N-qubit conditional phase gate directly. Our scheme employs a cavity input-output process and single-photon interference, without the use of any auxiliary entanglement pair or classical communication. Considering the currently available technologies, our scheme might be quite useful among different nodes in quantum networks for large-scaled QIP.展开更多
We design proposals to generate a remote Greenberger-Horne-Zeilinger（GHZ） state and a W state of nitrogenvacancy（NV） centers coupled to microtoroidal resonators（MTRs） through noisy channels by utilizing time-bin...We design proposals to generate a remote Greenberger-Horne-Zeilinger（GHZ） state and a W state of nitrogenvacancy（NV） centers coupled to microtoroidal resonators（MTRs） through noisy channels by utilizing time-bin encoding processes and fast-optical-switch-based polarization rotation operations.The polarization and phase noise induced by noisy channels generally affect the time of state generation but not its success probability and fidelity.Besides,the above proposals can be generalized to n-qubit between two or among n remote nodes with success probability unity under ideal conditions.Furthennore,the proposals are robust for regular noise-changeable channels for the n-node case.This method is also useful in other remote quantum information processing tasks through noisy channels.展开更多
Nitrogen-15 isotope-modified compounds are widely used in medicine, pharmacology, agriculture and various fields of science and their nomenclature is gradually increasing. Their widespread use depends on the availabil...Nitrogen-15 isotope-modified compounds are widely used in medicine, pharmacology, agriculture and various fields of science and their nomenclature is gradually increasing. Their widespread use depends on the availability of inexpensive and simple isotope analysis methods. The present article is an attempt to determine the nitrogen-15 isotope content directly in organic compounds without their conversion. The general principle of possibility of determination of the isotopes of nitrogen directly in organic compounds is proposed. Based on the study of mass-spectra of Carbamide Carbonyldiamide, isocyanic acid and nitrobenzene the mass peaks are selected, by which it is possible to determine the atomic fraction of the isotopes of nitrogen. The respective formulas are proposed.展开更多
In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magne...In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magnetometer studied can reduce the frequency noise of system and improve the magnetic sensitivity by microwave frequency modulation.Firstly,ESR spectra by sweeping the microwave frequency was obtained.Further,the microwave frequency modulated was gained through the mixed high-frequency sinusoidal modulation signal generated by signal generator.In addition,the frequency through the lock-in amplifier was locked,and the signal which was proportional to the first derivative of the spectrum was obtained.The experimental results show that the sensitivity of magnetic field detection can reach 17.628 nT/Hz based on microwave frequency modulation technology.The method realizes high resolution and sensitivity for magnetic field detection.展开更多
Diamond negatively charged nitrogen-vacancy(NV-) centers provide an opportunity for the measurement of the Meissner effect on extremely small samples in a diamond anvil cell(DAC) due to their high sensitivity in detec...Diamond negatively charged nitrogen-vacancy(NV-) centers provide an opportunity for the measurement of the Meissner effect on extremely small samples in a diamond anvil cell(DAC) due to their high sensitivity in detecting the tiny change of magnetic field. We report on the variation of magnetic field distribution in a DAC as a sample transforms from normal to superconducting state by using finite element analysis. The results show that the magnetic flux density has the largest change on the sidewall of the sample, where NV-centers can detect the strongest signal variation of the magnetic field. In addition, we study the effect of magnetic coil placement on the magnetic field variation. It is found that the optimal position for the coil to generate the greatest change in magnetic field strength is at the place as close to the sample as possible.展开更多
In this paper, we have reported an investigation on the evolution of nitrogen structures in diamond crystals which contain nitrogen donor atoms in the range of 1500 ppm-1600 ppm following an annealing treatment at a h...In this paper, we have reported an investigation on the evolution of nitrogen structures in diamond crystals which contain nitrogen donor atoms in the range of 1500 ppm-1600 ppm following an annealing treatment at a high pressure of about 6.5 GPa and high temperatures of 1920 K-2120 K. The annealing treatment was found to completely transform nitrogen atoms originally arranged in a single substitutional form （C-center）, into a pair form （A-center）, indicated from infrared （IR） spectra. The photoluminescence （PL） spectra revealed that a small fraction of nitrogen atoms remained in C-center form, while some nitrogen atoms in A-center form were further transformed into N3 and H3 center structures. In addition, PL spectra have revealed the existence of two newly observed nitrogen-related structures with zero phonon lines at 611 nm and 711 nm. All these findings above are very helpful in understanding the formation mechanism of natural diamond stones of the Ia-type, which contains nitrogen atoms in an aggregated form.展开更多
Hybrid quantum system of negatively charged nitrogen–vacancy（NV^-） centers in diamond and superconducting qubits provide the possibility to extend the performances of both systems. In this work, we numerically simu...Hybrid quantum system of negatively charged nitrogen–vacancy（NV^-） centers in diamond and superconducting qubits provide the possibility to extend the performances of both systems. In this work, we numerically simulate the coupling strength between NV^-ensembles and superconducting flux qubits and obtain a lower bound of 1016cm^（-3） for NV^-concentration to achieve a sufficiently strong coupling of 10 MHz when the gap between NV^-ensemble and flux qubit is 0. Moreover, we create NV^-ensembles in different types of diamonds by14^（N＋）and12（C＋）ion implantation, electron irradiation, and high temperature annealing. We obtain an NV^-concentration of 1.05 × 1016cm^（-3） in the diamond with1-ppm nitrogen impurity, which is expected to have a long coherence time for the low nitrogen impurity concentration. This shows a step toward performance improvement of flux qubit-NV^-hybrid system.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Part of this project supported by the National Natural Science Foundation of China(Grant Nos.11375067,11275074,11104210,11004069,and 91021011)the Doctoral Foundation of the Ministry of Education of China(Grant No.20100142120081)the National Basic Research Program of China(GrantNo.2012CB922103)
文摘We investigate spontaneous emission properties and control of the zero phonon line （ZPL） from a diamond nitrogen- vacancy （NV） center coherently driven by a single ellipfically polarized control field. We use the Schrrdinger equation to calculate the probability amplitudes of the wave function of the coupled system and derive analytical expressions of the spontaneous emission spectra. The numerical results show that a few interesting phenomena such as enhancement, narrowing, suppression, and quenching of the ZPL spontaneous emission can be realized by modulating the polarization- dependent phase, the Zeeman shift, and the intensity of the control field in our system. In the dressed-state picture of the control field, we find that multiple spontaneously generated coherence arises due to three close-lying states decaying to the same state. These results are useful in real experiments.
基金Project supported by the National Fundamental Research Program of China(Grant No.2010CB923202)the Fundamental Research Funds for the Central Universities,Chinathe National Natural Science Foundation of China(Grant Nos.61177085,61205117,and 61377097)
文摘Implementation of a nonlocal multi-qubit conditional phase gate is an essential requirement in some quantum infor- mation processing （QIP） tasks. Recently, a novel solid-state cavity quantum electrodynamics （QED） system, in which the nitrogen-vacancy （NV） center in diamond is coupled to a microtoroidal resonator （MTR）, has been proposed as a poten- tial system for hybrid quantum information and computing. By virtue of such systems, we present a scheme to realize a nonlocal N-qubit conditional phase gate directly. Our scheme employs a cavity input-output process and single-photon interference, without the use of any auxiliary entanglement pair or classical communication. Considering the currently available technologies, our scheme might be quite useful among different nodes in quantum networks for large-scaled QIP.
基金supported by the National Natural Science Foundation of China(Grant Nos.11264042,61465013,11465020,and 11165015)the Program for Chun Miao Excellent Talents of Jilin Provincial Department of Education(Grant No.201316)the Talent Program of Yanbian University of China(Grant No.950010001)
文摘We design proposals to generate a remote Greenberger-Horne-Zeilinger（GHZ） state and a W state of nitrogenvacancy（NV） centers coupled to microtoroidal resonators（MTRs） through noisy channels by utilizing time-bin encoding processes and fast-optical-switch-based polarization rotation operations.The polarization and phase noise induced by noisy channels generally affect the time of state generation but not its success probability and fidelity.Besides,the above proposals can be generalized to n-qubit between two or among n remote nodes with success probability unity under ideal conditions.Furthennore,the proposals are robust for regular noise-changeable channels for the n-node case.This method is also useful in other remote quantum information processing tasks through noisy channels.
文摘Nitrogen-15 isotope-modified compounds are widely used in medicine, pharmacology, agriculture and various fields of science and their nomenclature is gradually increasing. Their widespread use depends on the availability of inexpensive and simple isotope analysis methods. The present article is an attempt to determine the nitrogen-15 isotope content directly in organic compounds without their conversion. The general principle of possibility of determination of the isotopes of nitrogen directly in organic compounds is proposed. Based on the study of mass-spectra of Carbamide Carbonyldiamide, isocyanic acid and nitrobenzene the mass peaks are selected, by which it is possible to determine the atomic fraction of the isotopes of nitrogen. The respective formulas are proposed.
基金National Natural Science Foundation of China(Nos.51635011,61503346,51727808)National Science Foundation of Shanxi Province(No.201701D121080)
文摘In view of the low resolution and accuracy of traditional magnetometer,a method of microwave frequency modulation technology based on nitrogen-vacancy(NV)center in diamond for magnetic detection was proposed.The magnetometer studied can reduce the frequency noise of system and improve the magnetic sensitivity by microwave frequency modulation.Firstly,ESR spectra by sweeping the microwave frequency was obtained.Further,the microwave frequency modulated was gained through the mixed high-frequency sinusoidal modulation signal generated by signal generator.In addition,the frequency through the lock-in amplifier was locked,and the signal which was proportional to the first derivative of the spectrum was obtained.The experimental results show that the sensitivity of magnetic field detection can reach 17.628 nT/Hz based on microwave frequency modulation technology.The method realizes high resolution and sensitivity for magnetic field detection.
基金supported by the National Key R&D Program of China(Grant No.2018YFA0305900)the National Natural Science Foundation of China(Grant Nos.11774126,11674404,and 51772125)
文摘Diamond negatively charged nitrogen-vacancy(NV-) centers provide an opportunity for the measurement of the Meissner effect on extremely small samples in a diamond anvil cell(DAC) due to their high sensitivity in detecting the tiny change of magnetic field. We report on the variation of magnetic field distribution in a DAC as a sample transforms from normal to superconducting state by using finite element analysis. The results show that the magnetic flux density has the largest change on the sidewall of the sample, where NV-centers can detect the strongest signal variation of the magnetic field. In addition, we study the effect of magnetic coil placement on the magnetic field variation. It is found that the optimal position for the coil to generate the greatest change in magnetic field strength is at the place as close to the sample as possible.
基金Project supported by the Natural Science Foundation of Heilongjiang Province,China(Grant No.E201341)the Open Research Program of Key Lab of Superhard Materials of Mudanjiang Normal College,China(Grant No.201302)
文摘In this paper, we have reported an investigation on the evolution of nitrogen structures in diamond crystals which contain nitrogen donor atoms in the range of 1500 ppm-1600 ppm following an annealing treatment at a high pressure of about 6.5 GPa and high temperatures of 1920 K-2120 K. The annealing treatment was found to completely transform nitrogen atoms originally arranged in a single substitutional form （C-center）, into a pair form （A-center）, indicated from infrared （IR） spectra. The photoluminescence （PL） spectra revealed that a small fraction of nitrogen atoms remained in C-center form, while some nitrogen atoms in A-center form were further transformed into N3 and H3 center structures. In addition, PL spectra have revealed the existence of two newly observed nitrogen-related structures with zero phonon lines at 611 nm and 711 nm. All these findings above are very helpful in understanding the formation mechanism of natural diamond stones of the Ia-type, which contains nitrogen atoms in an aggregated form.
基金Project supported in part by the National Natural Science Foundation of China(Grant Nos.91321208,11574386,11374344,and 11574380)the National Basic Research Program of China(Grant Nos.2014CB921401 and 2016YFA0300601)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB07010300)
文摘Hybrid quantum system of negatively charged nitrogen–vacancy（NV^-） centers in diamond and superconducting qubits provide the possibility to extend the performances of both systems. In this work, we numerically simulate the coupling strength between NV^-ensembles and superconducting flux qubits and obtain a lower bound of 1016cm^（-3） for NV^-concentration to achieve a sufficiently strong coupling of 10 MHz when the gap between NV^-ensemble and flux qubit is 0. Moreover, we create NV^-ensembles in different types of diamonds by14^（N＋）and12（C＋）ion implantation, electron irradiation, and high temperature annealing. We obtain an NV^-concentration of 1.05 × 1016cm^（-3） in the diamond with1-ppm nitrogen impurity, which is expected to have a long coherence time for the low nitrogen impurity concentration. This shows a step toward performance improvement of flux qubit-NV^-hybrid system.
