作者机构：
[Hu, Xiang-ming; Zou, Jin-hua] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, Xiang-ming] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We propose a scheme for generating a two-atom entangled state and an N-atom W state using adiabatic evolution of dark eigenstates in cavity QED. The time required to complete the process does not need precise control. Since the cavity modes are never excited during the operations by engineering adiabatic evolution and controlling the atom–cavity couplings, the decoherence of the cavity decay can be suppressed.
作者机构：
[Hu, Xiang-ming; Xu, Jun] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, Xiang-ming] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
42.50.Gy;32.80.Qk;32.80.Lg
摘要：
We show that the bichromatic phase control of the spontaneous emission spectrum leads to the sub-half-wavelength atom localization. We consider a three-level Λ-type atom interacting with a bichromatic coupling field and a bichromatic probe field with equal frequency difference. One component of the bichromatic coupling field is a standing-wave field with position dependent Rabi frequency. When the spontaneous emitted photons are detected, the atom is localized in either of the two half-wavelength regions with 50% probability by the variation of the difference between the relative phases of the two bichromatic fields.
作者机构：
[Hu, Xiang-ming; Wang, Tan] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, Xiang-ming] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We present sideband control of optical bistability and multistability based on trichromatic electromagnetic-field induced transparency and quantum interference. Appearance or disappearance of the bistability and multistability, manipulation of the hysteresis loop widths, and switching between bistability and tristability are achieved simply by varying the sideband amplitudes or the relative phases of the sidebands to the central component. (C) 2007 Elsevier B.V. All rights reserved.
作者机构：
[Hu, Xiang-Ming; Xu, Jun] Department of Physics, Huazhong Normal University, Wuhan 430079, China
通讯机构：
[Hu, Xiang-Ming] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We propose a scheme of atom localization based on the interaction of the atom in the Λ configuration with a strong bichromatic coupling field and a weak bichromatic probe field with equal frequency difference. One of the bichromatic coupling components is a standing-wave field, which imposes position information on the Rabi frequency. By varying the difference between the relative phases of the two bichromatic fields, the atom is localized in either of the two half-wavelength regions with 50% probability provided the population in the upper state is detected.
作者机构：
[Hu Xiang-Ming; Yang Jin-Jin] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu Xiang-Ming] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
Linewidth;One-Atom;Dressed-State
摘要：
We examine the effects of driving field linewidth on a one-atom dressed state laser. Unexpectedly, the linewidth leads to anomalous effects on the cavity field. The mean photon number of the cavity field is raised or the normalized variance is reduced to a certain degree as the linewidth increases for an appropriate range of parameters. The responsible mechanism is attributed to the fluctuation-induced modification of the electromagnetic reservoir where the atom stays.
作者机构：
[Hu Xiang-Ming; Wang Jian] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu Xiang-Ming] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
关键词：
Population;Modulated;Fluctuating
摘要：
We examine the effects of cross correlated phase fluctuations on the coherent population trapping (CPT) induced by a pair of phase-modulated fields with equal modulation frequencies in a three-level Λ system. The maximal coherence of -0.5, which appears when CPT occurs for equal modulation indices, is preserved in the presence of the critically cross-correlated fluctuations. Unexpectedly, the non-maximal coherence, which is established when CPT is obtained for different modulation indices, is significantly enhanced due to the critically cross-correlated fluctuations.
作者机构：
[Hu, Xiang-Ming; Xu, Jun] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Xu, Jun] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We show that it is possible to localize a two-level atom as it passes through a standing-wave field by measuring the probe-field absorption. There is 50% detecting probability of the atom at the nodes of the standing-wave field in the subwavelength domain when the probe field is tuned resonant with the atomic transition. (c) 2006 Elsevier B.V. All rights reserved.
作者机构：
[Hu, Xiang-ming; Wang, Fei] Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Hu, Xiang-ming] H;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
摘要：
We show that strongly correlated and anticorrelated photons can be produced from two fluorescent fields emitted by a driven cascade atom with split metastable states. Depending on the choice of parameters, we have strong correlations for both fluorescent fields, anticorrelations for both, and strong correlation for one and anticorrelation for the other. In the presence of level splitting, we have two interfering cascade-dressed transitions from the top state to the antisymmetric superposition of the metastable states. The interference between the two cascade-dressed transitions is responsible for the strong correlations and anticorrelations.
作者机构：
[Zhang, Jiepeng] Florida Int Univ, Dept Phys, Miami, FL 33199 USA.;Huazhong Normal Univ, Dept Phys, Wuhan 430079, Peoples R China.
通讯机构：
[Zhang, Jiepeng] F;Florida Int Univ, Dept Phys, Miami, FL 33199 USA.
摘要：
We report an experimental study of atomic coherence and interference in a three-level Λ system of cold Rb atoms driven by multicolor coupling and probe fields. The multicolor coupling and probe fields open multiple channels for a two-photon Raman process. Interference between the open channels leads to rich spectral features in the Λ system and can be controlled by the phase of the probe field. The constructive-interference-induced transparency or the destructive-interference-induced absorption with a subnatural linewidth can be selectively created near the atomic resonance.
摘要：
Effects of the antirotating coupling on the absorption resonances are presented for a microwave driven three-level system. It is shown that nonlinear sideband generation, selective suppression and switching between peaks and dips in the absorption spectrum are obtained as the microwave Rabi frequency is varied. A physical explanation is given in terms of the coherent superposition of an infinite set of transitions that are associated with an infinite set of dressed states, which are created by the rotating and nonrotating couplings as the equivalent bichromatic excitation.
