Unified and standardized solving formulas for eigenvalues,eigenvectors,evolution operators,time-varying atomic inversion and photon numbers are given to single-mode Jaynes-Cummings models with any forms of intensity-d...Unified and standardized solving formulas for eigenvalues,eigenvectors,evolution operators,time-varying atomic inversion and photon numbers are given to single-mode Jaynes-Cummings models with any forms of intensity-dependent atom-field coupling and the nonlinearity of the quantized photonic field itself such as the Kerr effect.展开更多
The effect of double frequency oftrap fieldφ=U-V1 cosΩt-V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a...The effect of double frequency oftrap fieldφ=U-V1 cosΩt-V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a trapped ion are plotted and some meaningful physical results are shown.展开更多
The optical frequency of the 4s2S1/2 3d2 Ds/2 transition in a single trapped and laser-cooled 40 Ca＋ ion is measured with an optical frequency comb system referenced to a hydrogen maser, A 729-nm laser can be locked ...The optical frequency of the 4s2S1/2 3d2 Ds/2 transition in a single trapped and laser-cooled 40 Ca＋ ion is measured with an optical frequency comb system referenced to a hydrogen maser, A 729-nm laser can be locked to the clock transition about ten hours and the Allan deviation is better than 2 × 10-14/1000s.展开更多
We propose a scheme to purify entanglement of two atoms from not-too-impure entangled states by checking the parity of the two atoms through the cavity input-output process. As the parity check is made by measurement ...We propose a scheme to purify entanglement of two atoms from not-too-impure entangled states by checking the parity of the two atoms through the cavity input-output process. As the parity check is made by measurement on single-photon polarization, which would not affect the entanglement of the two atoms, our scheme has the successful probability double of that in a previous well-known scheme with linear optical elements [Nature （London） 410 （2001） 1067], and is insensitive to the photon loss and the detection inefficieney. Experimental feasibility of our scheme with current technology is discussed.展开更多
We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially e...We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially entangled states in cavity QED. Our scheme can preserve the internal structure of the entangled states above, with only generation of a global phase corresponding to each of entangled states during the storage of them. One single-mode cavity and n identical two-level atoms are required. Our scheme may be realized in the present technology. The idea may be also utilized to store multi-trapped-ion entangled states in linear ion trap.展开更多
The charge transfer rate coefficients for reactions of Sc^(3+)with N_(2) and H_(2) have been measured at the mean collision energy of 4.2eV.The rate coefficients are derived from the decay rate of ion signals by using...The charge transfer rate coefficients for reactions of Sc^(3+)with N_(2) and H_(2) have been measured at the mean collision energy of 4.2eV.The rate coefficients are derived from the decay rate of ion signals by using ion storage in a radio-frequency ion trap.The rate coefficients are 8.18(0.18)×10^(-10)cm^(3)·s^(-1) at Tequiv≈1.26×10^(4)K for Sc^(3+) with N_(2) and 1.44(0.39)×10^(-9)cm^(3)·s^(-1) at Tequiv>≈1.67×10^(3) K for Sc^(3+) with H_(2),respectively.Both results are comparable with the Langevin rate coefficients.展开更多
Superpositional wave function oscillations for the implementation of quantum algorithms modify the desired interference required for the quantum computation. We propose a scheme with trapped ultracold ion-pairs being ...Superpositional wave function oscillations for the implementation of quantum algorithms modify the desired interference required for the quantum computation. We propose a scheme with trapped ultracold ion-pairs being qubits to diminish the detrimental effect of the wave function oscillations, which is applied to the two-qubit Grover's search. It can be also found that the qubits in our scheme are more robust against the decoherence caused by the environment, and the model is scalable.展开更多
Introducing a dressed-state description,we show that a trapped ion in a standing wave field can be described by a nonlinear Jaynes-Cummings model different from the counterpart of Vogel and Matos Filho[Phys.Rev.A 52(1...Introducing a dressed-state description,we show that a trapped ion in a standing wave field can be described by a nonlinear Jaynes-Cummings model different from the counterpart of Vogel and Matos Filho[Phys.Rev.A 52(1995)4214]in several aspects,which may carry important implications for the preparation and reconstruction of the nonclassical states of a trapped ion.展开更多
Variations of the hysteresis of the rf detection signals corresponding to the axial motion of an ion cloud in a Paul trap versus the detection voltage,operation parameters and number of ions have been observed.The fea...Variations of the hysteresis of the rf detection signals corresponding to the axial motion of an ion cloud in a Paul trap versus the detection voltage,operation parameters and number of ions have been observed.The features are explained by an extended pseudopotential model with an octupole potential correction and an effective potential from the ion cloud.展开更多
The average kinetic energy of 40 Ca＋ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca＋ varies from 0.5eV to 0.2eV with changing buffer gas pressure from 10^-7 ...The average kinetic energy of 40 Ca＋ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca＋ varies from 0.5eV to 0.2eV with changing buffer gas pressure from 10^-7 mbar to 10^-5 mbar. The Brownian motion model is also introduced to calculate the average kinetic energy of the trapped ions.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grant Nos.69688004 and 69788002the National Laboratory of MRAMP at Wuhan Institute of Physics and Mathematics,Chinese Academy of Sciences.
文摘Unified and standardized solving formulas for eigenvalues,eigenvectors,evolution operators,time-varying atomic inversion and photon numbers are given to single-mode Jaynes-Cummings models with any forms of intensity-dependent atom-field coupling and the nonlinearity of the quantized photonic field itself such as the Kerr effect.
基金The project supported by National Natural Science Foundation of China under Grant Nos 19904013 and 1904014
文摘The effect of double frequency oftrap fieldφ=U-V1 cosΩt-V2 cos 2Ωt in a Paul trap can be described exactly by using a function series expansion to solve the corresponding Mathieu equation.The stability regions of a trapped ion are plotted and some meaningful physical results are shown.
基金Supported by the National Basic Research Program of China under Grant No 2005CB724500, the National Natural Science Foundation of China under Grant Nos 60490280, 10774161, 10504038 and 10874205, and Chinese Academy of Sciences （YOL2081001）.
文摘The optical frequency of the 4s2S1/2 3d2 Ds/2 transition in a single trapped and laser-cooled 40 Ca＋ ion is measured with an optical frequency comb system referenced to a hydrogen maser, A 729-nm laser can be locked to the clock transition about ten hours and the Allan deviation is better than 2 × 10-14/1000s.
基金supported by National Natural Science Foundation of China under Grant Nos.10774163,10774042,and 10747167the State Key Basic Research Program of China under Grant Nos.2005CB724502 and 2006CB921203
文摘We propose a scheme to purify entanglement of two atoms from not-too-impure entangled states by checking the parity of the two atoms through the cavity input-output process. As the parity check is made by measurement on single-photon polarization, which would not affect the entanglement of the two atoms, our scheme has the successful probability double of that in a previous well-known scheme with linear optical elements [Nature （London） 410 （2001） 1067], and is insensitive to the photon loss and the detection inefficieney. Experimental feasibility of our scheme with current technology is discussed.
基金The project partially supported by Natural Science Foundation of Hunan Province of China under Grant No. 05JJ30005, the Science Research Fund of Educational Department of Hunan Province under Grant Nos. 05C756 and 06C766, National Natural Science Foundation of China under Grant Nos. 10274093 and 10474118, the Foundation for Youth Core-Teachers of Hunan Province under Grant No. 2003165, and the Science Research Fund of Hunan Institute of Humanity and Science and Technology under Grant No. 2005A001.We would like to thank Dr. Wen-Xing Yang and Xiao-Long Zhang for many helpful discussions.
文摘We propose a scheme for robustly storing multi-atom entangled states involving Bell states, three-particle W-state, n-particle W-like-states, generalized multi-particle W-states, n-particle GHZ-states, and partially entangled states in cavity QED. Our scheme can preserve the internal structure of the entangled states above, with only generation of a global phase corresponding to each of entangled states during the storage of them. One single-mode cavity and n identical two-level atoms are required. Our scheme may be realized in the present technology. The idea may be also utilized to store multi-trapped-ion entangled states in linear ion trap.
基金Supported by the National Natural Science Foundation of China under Grant No.19804015.
文摘The charge transfer rate coefficients for reactions of Sc^(3+)with N_(2) and H_(2) have been measured at the mean collision energy of 4.2eV.The rate coefficients are derived from the decay rate of ion signals by using ion storage in a radio-frequency ion trap.The rate coefficients are 8.18(0.18)×10^(-10)cm^(3)·s^(-1) at Tequiv≈1.26×10^(4)K for Sc^(3+) with N_(2) and 1.44(0.39)×10^(-9)cm^(3)·s^(-1) at Tequiv>≈1.67×10^(3) K for Sc^(3+) with H_(2),respectively.Both results are comparable with the Langevin rate coefficients.
基金Supported by the National Natural Science Foundation of China under Grant No.19904013.
文摘Superpositional wave function oscillations for the implementation of quantum algorithms modify the desired interference required for the quantum computation. We propose a scheme with trapped ultracold ion-pairs being qubits to diminish the detrimental effect of the wave function oscillations, which is applied to the two-qubit Grover's search. It can be also found that the qubits in our scheme are more robust against the decoherence caused by the environment, and the model is scalable.
基金Supported in part by the National Natural Science Foundation of China under Grant No.69688004,69788002the Trans-Century Training Programme Foundation for the Talents by the Chinese State Education Commissionthe National Laboratory of MRAMP at Wuhan Institute of Physics and Mathematics,Chinese Academy of Sciences.
文摘Introducing a dressed-state description,we show that a trapped ion in a standing wave field can be described by a nonlinear Jaynes-Cummings model different from the counterpart of Vogel and Matos Filho[Phys.Rev.A 52(1995)4214]in several aspects,which may carry important implications for the preparation and reconstruction of the nonclassical states of a trapped ion.
基金Supported by the National Natural Science Foundation of China under Grant No.19674066.
文摘Variations of the hysteresis of the rf detection signals corresponding to the axial motion of an ion cloud in a Paul trap versus the detection voltage,operation parameters and number of ions have been observed.The features are explained by an extended pseudopotential model with an octupole potential correction and an effective potential from the ion cloud.
基金Supported by the National Basic Research Program of China under Grant No 2005CB724500, and the National Natural Science Foundation of China under Grant Nos 60490280 and 10874205.
文摘The average kinetic energy of 40 Ca＋ ions is measured by the method of evaporating ions in an rf ion trap. The kinetic energy of the ion 40Ca＋ varies from 0.5eV to 0.2eV with changing buffer gas pressure from 10^-7 mbar to 10^-5 mbar. The Brownian motion model is also introduced to calculate the average kinetic energy of the trapped ions.
