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1.
We theoretically investigate the emission spectrum for a Λ-type three-level atom trapped in the node of a standing wave. We show that the atomic center-of-mass motion not only directly affects the peak number, peak position, and peak height in the atomic emission spectrum, but also influences the effects of the cavity field and the atomic initial state on atomic emission spectrum. 相似文献
2.
We study the interaction of a three-level atom with a single-mode field in a cavity. We take explicitly into account the existence of the forms of nonlinearities of both the field and the intensity-dependent atom-field coupling. The wavefunction for the atomic system of the Ξ configuration is obtained when the atom is initially prepared in the excited state. The electromagnetic field may assume a squeezed coherent or binomial state. The analytical forms of the fluorescence and absorption spectra are calculated using the dressed states of the system. We investigate the influences of the mean number of photons, detunings, and the nonlinearities forms on the spectrum of the resulting field states. It is shown that the features of the fluorescence and absorption spectra are influenced significantly by the kinds of nonlinearities. 相似文献
3.
X. Q. Jiang Y. L. Wang X. D. Sun 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(3):427-430
We study the spontaneous emission spectrum of a three-level Λ-type
atom in a damped cavity using the resolvent operator. The shape of the
spectrum is strongly influenced by the detuning and the coupling intensity
between the atom and the cavity mode. Especially, we find that the
splittings of the upper level of the three-level Λ-type atom are
different in strong coupling regime, intermediate coupling regime and weak
coupling regimes. 相似文献
4.
Mechanical effects of light on the Ξ-type three-level atom in a high-finesse optical cavity 下载免费PDF全文
A theoretical study is carried out for the modification and implication of the effect on the Ξ-type three level atom in a high-finesse optical cavity driven by light field including spontaneous emission and the cavity decay. Analytic expressions for the dipole force, the friction force, the optical potentials and the friction coefficient are obtained. Then the numerical and graphical methods are used to investigate the friction coefficient with the controlling parameters. It is shown that the friction coefficient is strongly dependent on the controlling parameters. The cooling rate can increase by one order of magnitude more than that of a two-level atomic system. The reason can be given using the dressed states and the Sisyphus cooling mechanism, which would stimulate further experimental investigations. 相似文献
5.
Electromagnetically induced transparency of single Λ-type three-level atom in high-finesse optical cavity 下载免费PDF全文
We study the features of the electromagnetically induced transparency (EIT) in a single Λ-type three-level atom placed in a high finesse cavity under the action of a coupling laser and a probe laser. Our calculations show that three transparency windows appear when the pump strength is big enough. It can be explained by the residual pump in the cavity resulting mostly in the energy splitting. Level |3〉is split into four slightly different energy levels. An interference takes place between excitation pathways. Furthermore, it is also shown that the frequencies of the EIT windows can be tuned by changing the coupling field detuning Δ2 and the reflection profile is very sensitive to the cavity field detuning Δc. 相似文献
6.
7.
<正>We study the non-classical properties of the single-mode electro-magnetic field resulting from the interaction of a S-type three-level atom initially in the coherent state,such as squeezing properties and sub-Poisson statistics.We show that if there are more photons in the cavity,the squeezing will appear earlier and be stronger under the same state,but the sub-Poisson statistics will be weaker,while sub-Poisson statistics and squeezing are more pronounced after the selective atomic measurement. 相似文献
8.
The two models of three-level (one upper level and two lower levels, or two upper levels and one lower level) atom embedded in a double-band photonic crystal are adopted. The atomic transitions from the upper levels to the lower levels are assumed to be coupled by the same reservoir which are respectively the isotropic photonic band gap (PBG) modes, the anisotropic PBG modes and the free vacuum modes. The effects of the fine structure of the atomic ground state levels in the model with one upper level and two lower levels, and the quantum interferences in the model with two upper levels and one lower level on the spontaneous emission spectrum of an atom are investigated in detail. Most interestingly, it is shown that new spontaneous emission lines are produced from the fine splitting of atomic ground state levels in the isotropic PBG case. The quantum interferences induce additional narrow spontaneous lines near the transition from the empty upper level to the lower level. 相似文献
9.
The nonlinear theory of interaction between the q analogue of a single-mode field and a Ξ-type threelevel atom has been established. And the formal solution of the Schrodinger equation in the representation and its average number are obtained. Then, the photon squeezing effects are studied through numerical calculation. The results show that the q deformation nonlinear action has a lot of influence on the quantum coherence and quantum properties. When q approaches 1, the theory reduces to the common linear theory. 相似文献
10.
The nonlinear theory of interaction between the q analogue of a single-mode field and a Ξ-type three-level atom has been established. And the formal solution of the Schrodinger equation in the representation and its average number are obtained. Then, the photon squeezing effects are studied through numerical calculation. The results show that the q deformation nonlinear action has a lot of influence on the quantum coherence and quantum properties. When q approaches 1, the theory reduces to the common linear theory. 相似文献
11.
In this paper thermal entanglement between two identical two-level atoms within a bichromatic cavity including Kerr nonlinear coupler is investigated. In this study, besides atom–field interaction, the field–field (via linear and Kerr-type couplings) and atomic dipole–dipole interactions are also included. It is also assumed that the cavity is held at a temperature T, so that all atom–photon states with probabilities defined by Boltzmann factor are present. Using a canonical transformation, the presented model is converted to a generalized form of Jaynes–Cummings model. After introducing Casimir operators of the system, it is shown that the Hamiltonian representation is block-diagonal. Diagonalizing each block, the thermal (Gibb’s) density matrix, written in the bases of total Hamiltonian, is obtained. The reduced atomic density matrix and consequently the concurrence, as a measure of entanglement, are obtained by partial tracing of thermal density matrix over the bichromatic photonic states. The concurrence vanishes at zero temperature, indicating that the ground state is separable, exhibits a maximal at a critical temperature and terminates at a finite temperature. The influences of coupler nonlinearities and dipole–dipole coupling on the thermal atom–atom entanglement are also addressed in detail. 相似文献
12.
Interaction of pair coherent state with a three-level Λ-type atom and generation of a modified Bessel-Gaussian state with a vortex structure 下载免费PDF全文
The evolution of a system state is derived based on the nonresonant interaction of a three-level "Λ" type atom with two cavity modes at a pair coherent state and two classic fields, and a cavity field state is analysed in detail under conditional detecting. It is found that the quantized modified Bessel-Gaussian states as well as the superposition states consisting of the quantized vortex states with different weighted coefficients may be prepared through carefully preparing an initial atomic state and appropriately adjusting the interaction time. The scheme provides an additional choice to realize the two-mode quantized vortex state within the context of cavity quantum electrodynamics (QED). 相似文献
13.
Interaction of a pair coherent state with a three-level Λ-type atom and generation of a modified Bessel-Gaussian state with a vortex structure 下载免费PDF全文
The evolution of a system state is derived based on the nonresonant interaction of a three-level "Λ" type atom with two cavity modes at a pair coherent state and two classic fields,and a cavity field state is analyzed in detail under conditional detecting.It is found that the quantized modified Bessel-Gaussian states as well as the superposition states consisting of the quantized vortex states with different weighted coefficients may be prepared through carefully preparing an initial atomic state and appropriately adjusting the interaction time.The scheme provides an additional choice to realize the two-mode quantized vortex state within the context of cavity quantum electrodynamics(QED). 相似文献
14.
A scheme for conditional quantum phase gate viabimodal cavity and a Λ-type three-level atom 下载免费PDF全文
We propose a scheme to implement a two-qubit conditional quantum
phase gatefor the intracavity field viaa single three-level
$\Lambda$-type atom driven by two modes in a high-Q cavity. The
quantum information is encoded on the Fock states of the bimodal
cavity. The gate's averaged fidelity is expected to reach $99.8\%$. 相似文献
15.
Entanglement and coherence of a three-level atom in Λ configuration interacting with two fields 下载免费PDF全文
We investigate the entanglement of a three-level atom in λ
configuration interacting with two quantized field modes by using
logarithmic negativity. Then, we study the relationship of the
atomic coherence and the entanglement between two fields which are
initially prepared in vacuum or thermal states. We find that if the
two fields are prepared in thermal states, the atomic coherence can
induce the entanglement between two thermal fields. However, there
is no coherence-induced entanglement between two vacuum fields. 相似文献
16.
Electromagnetically induced transparency of single Λ-type three-level atoms in a high-finesse optical cavity 下载免费PDF全文
We study the features of electromagnetically induced transparency(EIT) in a single Λ-type three-level atom placed in a high-finesse cavity under the action of a coupling laser and a probe laser.Our calculations show that three transparency windows appear when the pump strength is large enough.This can be explained by the residual pump in the cavity mostly resulting in energy splitting.The level |3 is split into four slightly different energy levels,and interference takes place between the excitation pathways.Furthermore,it is also shown that the frequencies of the EIT windows can be tuned by changing the coupling field detuning 2,and that the reflection profile is very sensitive to the cavity field detuning △c. 相似文献
17.
《中国物理 B》2015,(11)
We measure the absorption and dispersion in a Doppler-broadened Λ-type three level system by resonant stimulated Raman spectroscopy with homodyne detection. Through studying the dressed state energies of the system, it is found that the absorption and dispersion satisfy the Kramers–Kronig relation. The absorption and dispersion spectra calculated by employing this relation agree well with our experimental observations. 相似文献
18.
Phase-controlled atom-photon entanglement in a three-level Λ-type closed-loop atomic system 下载免费PDF全文
We study the entanglement of dressed atom and its spontaneous emission in a three-level Λ-type closed-loop atomic system in a multi-photon resonance condition and beyond it.It is shown that the von Neumann entropy in such a system is phase-dependent,and it can be controlled by either the intensity or relative phase of applied fields.It is demonstrated that for the special case of the Rabi frequency of applied fields,the system is disentangled.In addition,we take into account the effect of Doppler broadening on the entanglement and it is found that a suitable choice of laser propagation direction allows us to obtain the steady state degree of entanglement(DEM) even in the presence of the Doppler effect. 相似文献
19.
《中国光学快报(英文版)》2008,(5)
The Kerr nonlinearity of a left-handed material is analyzed in a four-level atomic system.It is shown that, due to the effect of quantum interference,a large enhanced Kerr nonlinearity accompanied by vanishing absorption can be realized via choosing appropriate parameters in this negative refraction atomic medium. It not only shows the large nonlinearity but also acts as the phase and amplitude compensating effects. 相似文献
20.
L. Tan L. W. Liu Y. F. Sun 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,61(1):161-169
A theoretical study is carried out for the cavity
cooling of a Λ-type three-level atom in a high-finesse
optical cavity driven by a weakly field. Analytical expressions
for the friction, diffusion coefficients and the equilibrium
temperature are obtained by using the Heisenberg equations, then
they are calculated numerically and shown graphically as functions
of the controlling parameters. For a suitable choice of these
parameters, the dynamics of the cavity field interaction with the
Λ-type three-level atom introduces a sisyphus cooling
mechanism yielding lower temperature than the one of the two-level
atom, avoiding the problems induced by spontaneous emission. 相似文献