Role of phase fluctuation and dephasing in the enhancing continuous variable entanglement of a two-photon coherent beat laser

doi:10.1088/1674-1056/21/1/014204

摘要/Abstract

摘要： A steady state analysis of the nonclassical features and statistical properties of the cavity radiation of a two-photon coherent beat laser is presented. Results show that the degree of two-mode squeezing, detectable entanglement and intensity of the cavity radiation can increase with the deviation of the phase fluctuations of the laser employed in preparing the atoms, but decrease with the increasing rate at which the induced coherence superposition decays. Although it is found that varying the phase fluctuations and dephasing can lead to modification in the quantum features and statistical properties of the radiation, it does not alter the similarity in the nature of the degree of entanglement detectable by the criteria following from Duan-Giedke-Cirac-Zoller and logarithmic negativity in a perceivable manner. Since the intensity and quantum features can be readily enhanced, this system is expected to be a viable source of a strong robust entangled (squeezed) light under various conditions. Moreover, comparison of the mean number of photon pairs with intensity difference shows that the chance of inciting a two-photon process can be enhanced by changing the rate of dephasing and phase fluctuations.

关键词: coherent beat laser, phase fluctuations, dephasing, entanglement

Abstract: A steady state analysis of the nonclassical features and statistical properties of the cavity radiation of a two-photon coherent beat laser is presented. Results show that the degree of two-mode squeezing, detectable entanglement and intensity of the cavity radiation can increase with the deviation of the phase fluctuations of the laser employed in preparing the atoms, but decrease with the increasing rate at which the induced coherence superposition decays. Although it is found that varying the phase fluctuations and dephasing can lead to modification in the quantum features and statistical properties of the radiation, it does not alter the similarity in the nature of the degree of entanglement detectable by the criteria following from Duan-Giedke-Cirac-Zoller and logarithmic negativity in a perceivable manner. Since the intensity and quantum features can be readily enhanced, this system is expected to be a viable source of a strong robust entangled (squeezed) light under various conditions. Moreover, comparison of the mean number of photon pairs with intensity difference shows that the chance of inciting a two-photon process can be enhanced by changing the rate of dephasing and phase fluctuations.

Key words: coherent beat laser, phase fluctuations, dephasing, entanglement

中图分类号:

42.50.Ar

42.50.Gy (Effects of atomic coherence on propagation, absorption, and Amplification of light; electromagnetically induced transparency and Absorption) 42.50.Lc (Quantum fluctuations, quantum noise, and quantum jumps) 03.65.Ud (Entanglement and quantum nonlocality)

Sintayehu Tesfa. Role of phase fluctuation and dephasing in the enhancing continuous variable entanglement of a two-photon coherent beat laser[J]. 中国物理B, 2012, 21(1): 14204-014204.

Sintayehu Tesfa . Role of phase fluctuation and dephasing in the enhancing continuous variable entanglement of a two-photon coherent beat laser[J]. Chin. Phys. B, 2012, 21(1): 14204-014204.

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