We consider, from the point of view of a coaccelerated frame, a uniformly accelerated multi-level atom in interaction with vacuum quantum electromagnetic fields in the multi-polar coupling scheme, and calculate the ra...We consider, from the point of view of a coaccelerated frame, a uniformly accelerated multi-level atom in interaction with vacuum quantum electromagnetic fields in the multi-polar coupling scheme, and calculate the rate of change of the atom＇s energy assuming a thermal bath at a finite temperature T in the Rindler wedge. Comparison with the spontaneous excitation rate of the atom calculated in the instantaneous inertial frame of the atom shows that both the inertial and coaccelerated observer would agree with each other only when the temperature of the thermal bath equals the FDU value TFDU = α/2π.展开更多
We propose a scheme to implement a quantum controlled-NOT (CNOT) gate between two four-level atoms inside the detuned optical cavity. The system state is evolved inside the decoherence-free (DF) subspace through stimu...We propose a scheme to implement a quantum controlled-NOT (CNOT) gate between two four-level atoms inside the detuned optical cavity. The system state is evolved inside the decoherence-free (DF) subspace through stimulated Raman processes, which yields the desired unitary evolution operation for the CNOT. Our scheme is immune to decoherence due to dissipation of cavity excitation and spontaneous emission from the excited atomic level.展开更多
We study the energy level shifts of an accelerated multilevel atom in dipole coupling to the derivative of a quantum massless scalar field and separately calculate the contributions of vacuum fluctuations and radiatio...We study the energy level shifts of an accelerated multilevel atom in dipole coupling to the derivative of a quantum massless scalar field and separately calculate the contributions of vacuum fluctuations and radiation reaction to the shifts. It is found that, in contrast to the case of a monopole-like interaction, both the vacuum fluctuations and radiation reaction contributions are changed by acceleration, and they all contain non-thermal correction terms. Our results suggest that the effect of acceleration on the energy shifts is dependent on the type of the interaction between the atom and the quantum field.展开更多
We examine the phase-dependent effects in resonance fluorescence of a two-level atom driven by a trichromatic modulated field. It is shown that the fluorescence spectrum depends crucially on the sum of relative phases...We examine the phase-dependent effects in resonance fluorescence of a two-level atom driven by a trichromatic modulated field. It is shown that the fluorescence spectrum depends crucially on the sum of relative phases of the sideband components compared to the central component, not simply on the respective phases. The appearance or disappearance of the central peak and the selective elimination of the sideband peaks are achieved simply by varying the sum phase. Once the sum phase is fixed, the spectrum keeps its features unchanged regardless of the respective relative phases.展开更多
<正> In recent years, owing to the various applications in the unified theory of weakelectromagnetic interactions (Weinberg-Salam model), the confinement of quarks, SU(2) magnetic monopole, solitons and so on, t...<正> In recent years, owing to the various applications in the unified theory of weakelectromagnetic interactions (Weinberg-Salam model), the confinement of quarks, SU(2) magnetic monopole, solitons and so on, the Higgs field has been investigated by both classical and semi-classical approaches. Here, we shall search for the elementary excitation spectrum of the Higgs field by using the method analoggus to that in treating the superfluidity of ~4He by Bogoliubov, so as to find the relation between the spontaneously broken symmetry of vacuum and the Bose condensation.展开更多
基金Supported in part by the National Natural Science Foundation of China under Grants Nos 10575035 and 10775050, the Programme for NCET under Grant No 04-0784, the SRFDP under Grant No 20070542002, and the Programme for the Key Discipline in Hunan Province.
文摘We consider, from the point of view of a coaccelerated frame, a uniformly accelerated multi-level atom in interaction with vacuum quantum electromagnetic fields in the multi-polar coupling scheme, and calculate the rate of change of the atom＇s energy assuming a thermal bath at a finite temperature T in the Rindler wedge. Comparison with the spontaneous excitation rate of the atom calculated in the instantaneous inertial frame of the atom shows that both the inertial and coaccelerated observer would agree with each other only when the temperature of the thermal bath equals the FDU value TFDU = α/2π.
基金This work was supported in part by the National Natural Science Foundation of China under Grant No. 10275091.
文摘We propose a scheme to implement a quantum controlled-NOT (CNOT) gate between two four-level atoms inside the detuned optical cavity. The system state is evolved inside the decoherence-free (DF) subspace through stimulated Raman processes, which yields the desired unitary evolution operation for the CNOT. Our scheme is immune to decoherence due to dissipation of cavity excitation and spontaneous emission from the excited atomic level.
基金Supported by the National Natural Science Foundation of China under Grants Nos 10375023 and 10575035, the Programme for NCET （No 04-0784）, the Key Project of the Ministry of Education of China （No 205110）, and the National Basic Research Programme of China under Grant No 2003CB71630.
文摘We study the energy level shifts of an accelerated multilevel atom in dipole coupling to the derivative of a quantum massless scalar field and separately calculate the contributions of vacuum fluctuations and radiation reaction to the shifts. It is found that, in contrast to the case of a monopole-like interaction, both the vacuum fluctuations and radiation reaction contributions are changed by acceleration, and they all contain non-thermal correction terms. Our results suggest that the effect of acceleration on the energy shifts is dependent on the type of the interaction between the atom and the quantum field.
基金Supported by the National Natural Science Foundation of China under Grant No 60378008.
文摘We examine the phase-dependent effects in resonance fluorescence of a two-level atom driven by a trichromatic modulated field. It is shown that the fluorescence spectrum depends crucially on the sum of relative phases of the sideband components compared to the central component, not simply on the respective phases. The appearance or disappearance of the central peak and the selective elimination of the sideband peaks are achieved simply by varying the sum phase. Once the sum phase is fixed, the spectrum keeps its features unchanged regardless of the respective relative phases.
文摘<正> In recent years, owing to the various applications in the unified theory of weakelectromagnetic interactions (Weinberg-Salam model), the confinement of quarks, SU(2) magnetic monopole, solitons and so on, the Higgs field has been investigated by both classical and semi-classical approaches. Here, we shall search for the elementary excitation spectrum of the Higgs field by using the method analoggus to that in treating the superfluidity of ~4He by Bogoliubov, so as to find the relation between the spontaneously broken symmetry of vacuum and the Bose condensation.
