By using the normal ordering method, we study the state evolution of an optically driven excitons in a quantum well immersed in a leaky cavity, which was introduced by Yu-Xi Liu et al. [Phys. Rev. A 63 (2001) 033816]....By using the normal ordering method, we study the state evolution of an optically driven excitons in a quantum well immersed in a leaky cavity, which was introduced by Yu-Xi Liu et al. [Phys. Rev. A 63 (2001) 033816]. The influence of the external laser field on the quantum decoherence of a mesoscopically superposed state of the excitons is investigated. Our result shows that, the classical field can compensate the energy dissipation of the excitons. Although the decoherence rate of the excitonic Schr?dinger cat state does not depend on the external field, the phase of the decoherence factor can be well controlled by adjusting the amplitude of the external field as well as the detuning between the field and the transition frequency of the atom.展开更多
Stationary electrostatic-potential formation in plasma with immovable dustparticles was investigated by using one-dimensional kinetic analysis. It is clarified that thedensity of negatively charged dust particles belo...Stationary electrostatic-potential formation in plasma with immovable dustparticles was investigated by using one-dimensional kinetic analysis. It is clarified that thedensity of negatively charged dust particles below the threshold value makes the potential decreasemonoton-ically. When the dust densities are above the threshold, there appears the stationaryoscillation in an electrostatic potential due to the streaming plasma. It is found that thewavelength of this mode is of the order of Debye length. These phenomena are different from those ofthe conventional dust ion-acoustic waves in plasma, where the effect of dust-charging is not takeninto account.展开更多
文摘By using the normal ordering method, we study the state evolution of an optically driven excitons in a quantum well immersed in a leaky cavity, which was introduced by Yu-Xi Liu et al. [Phys. Rev. A 63 (2001) 033816]. The influence of the external laser field on the quantum decoherence of a mesoscopically superposed state of the excitons is investigated. Our result shows that, the classical field can compensate the energy dissipation of the excitons. Although the decoherence rate of the excitonic Schr?dinger cat state does not depend on the external field, the phase of the decoherence factor can be well controlled by adjusting the amplitude of the external field as well as the detuning between the field and the transition frequency of the atom.
文摘Stationary electrostatic-potential formation in plasma with immovable dustparticles was investigated by using one-dimensional kinetic analysis. It is clarified that thedensity of negatively charged dust particles below the threshold value makes the potential decreasemonoton-ically. When the dust densities are above the threshold, there appears the stationaryoscillation in an electrostatic potential due to the streaming plasma. It is found that thewavelength of this mode is of the order of Debye length. These phenomena are different from those ofthe conventional dust ion-acoustic waves in plasma, where the effect of dust-charging is not takeninto account.
