This paper proposes a simple scheme for generating a three-atom GHZ state via cavity quantum electrodynamics (QED). The task can be achieved through the interaction between two EPR states, which can be prepared easi...This paper proposes a simple scheme for generating a three-atom GHZ state via cavity quantum electrodynamics (QED). The task can be achieved through the interaction between two EPR states, which can be prepared easily with current technology. In this scheme, the cavity field is only virtually excited during the interaction process, and no quantum information transfer between the atoms and the cavity is required. Thus it greatly prolongs the efficient decoherent time. Moreover, this scheme is also applicable for generating an N-atom GHZ state.展开更多
A simple scheme is proposed to generate the W state of N A-type neutral atoms trapped in an optical cavity via Raman transition. Conditional on no photon leakage from the cavity, the N-qubit W state can be prepared pe...A simple scheme is proposed to generate the W state of N A-type neutral atoms trapped in an optical cavity via Raman transition. Conditional on no photon leakage from the cavity, the N-qubit W state can be prepared perfectly by turning on a classical coupling field for an appropriate time. Compared with the previous ones, our scheme requires neither individual laser addressing of the atoms, nor demand for controlling N atoms to go through an optical cavity simultaneously with a constant velocity. We investigate the influence of cavity decay using the quantum jump approach and show that the preparation time decreases and the success probability increases with atom number because of a collective enhancement of the coupling.展开更多
On the basis of the calculations and analyses of the intrapair and interpair correlation energy of KX (X = OH, NC) molecules and the results of the transferability of both the innermost intrapair correlation energy an...On the basis of the calculations and analyses of the intrapair and interpair correlation energy of KX (X = OH, NC) molecules and the results of the transferability of both the innermost intrapair correlation energy and the inner core effect of K and X in KX molecules, we defined and calculated the Kδ- and Xδ-correlation contributions to the total correlation energy of KX molecules. With the comparison of the pair correlation energy of K+, X- and KX systems, we present a simple estimation method to estimate the electron correlation energy of strong ionic compound by summarizing the correlation energy of its constituent ion and ionic group. By using this simple method, the reasonable estimation results of the correlation energy of (KOH)2 and (KNC)2 have been obtained at mp2/6-311++G(d) level with Gaussian98 program, and the deviations are very small. Applying the scheme of "Separate Large System into Smaller Ones" to the calculation of electron correlation energy of large ionic compounds, it can not展开更多
High-order harmonic generation from one-dimensional (1D) multi-atom molecular ions ill an ultra-short laser field is theoretically- investigated, The dynamics of the electron in a linearly polarized intense laser fi...High-order harmonic generation from one-dimensional (1D) multi-atom molecular ions ill an ultra-short laser field is theoretically- investigated, The dynamics of the electron in a linearly polarized intense laser field is analyzed in terms of 1D Schroedinger equation with the Crank-Nicolson algorithm, The dependence of high-order harmonics on the laser frequeney and the biter-nuclear distance is discussed, It is found that the optimum range of inter-nuclear distance should be changed to get extended harmonic generation for different laser frequency, and the lower frequency laser pulse is favorable to higher order harmonic generation as the inter-nuclear distance increases.展开更多
基金Project supported by the National Natural Science Foundation of China (Grant No 10574001) and the Program of the Education Department of Anhui Province (Grant No 2004kj029).
文摘This paper proposes a simple scheme for generating a three-atom GHZ state via cavity quantum electrodynamics (QED). The task can be achieved through the interaction between two EPR states, which can be prepared easily with current technology. In this scheme, the cavity field is only virtually excited during the interaction process, and no quantum information transfer between the atoms and the cavity is required. Thus it greatly prolongs the efficient decoherent time. Moreover, this scheme is also applicable for generating an N-atom GHZ state.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10504042)the Key Laboratory of Low Dimensional Quantum Structures and Quantum Control (Hunan Normal University)Ministry of Education of China (Grant No.QSQC0902)
文摘A simple scheme is proposed to generate the W state of N A-type neutral atoms trapped in an optical cavity via Raman transition. Conditional on no photon leakage from the cavity, the N-qubit W state can be prepared perfectly by turning on a classical coupling field for an appropriate time. Compared with the previous ones, our scheme requires neither individual laser addressing of the atoms, nor demand for controlling N atoms to go through an optical cavity simultaneously with a constant velocity. We investigate the influence of cavity decay using the quantum jump approach and show that the preparation time decreases and the success probability increases with atom number because of a collective enhancement of the coupling.
基金This work was supported by the National Natural Science Foundation of China (Grant Nos. 29873023 and 20173027).
文摘On the basis of the calculations and analyses of the intrapair and interpair correlation energy of KX (X = OH, NC) molecules and the results of the transferability of both the innermost intrapair correlation energy and the inner core effect of K and X in KX molecules, we defined and calculated the Kδ- and Xδ-correlation contributions to the total correlation energy of KX molecules. With the comparison of the pair correlation energy of K+, X- and KX systems, we present a simple estimation method to estimate the electron correlation energy of strong ionic compound by summarizing the correlation energy of its constituent ion and ionic group. By using this simple method, the reasonable estimation results of the correlation energy of (KOH)2 and (KNC)2 have been obtained at mp2/6-311++G(d) level with Gaussian98 program, and the deviations are very small. Applying the scheme of "Separate Large System into Smaller Ones" to the calculation of electron correlation energy of large ionic compounds, it can not
基金This work was supported by the Shanghai Priority Academic Discipline, the National Natural Science Foundation of China (No. 10234030 and 10374030)the National Key Project for Basic Research of China (No.1999075204)the Key Project sponsored by Shanghai Science and Technology Committee (No. 036105019and 03DJ14001)the Twilight Project sponsored by Shanghai Education Committee (No. 03SG23)
文摘High-order harmonic generation from one-dimensional (1D) multi-atom molecular ions ill an ultra-short laser field is theoretically- investigated, The dynamics of the electron in a linearly polarized intense laser field is analyzed in terms of 1D Schroedinger equation with the Crank-Nicolson algorithm, The dependence of high-order harmonics on the laser frequeney and the biter-nuclear distance is discussed, It is found that the optimum range of inter-nuclear distance should be changed to get extended harmonic generation for different laser frequency, and the lower frequency laser pulse is favorable to higher order harmonic generation as the inter-nuclear distance increases.