共查询到17条相似文献,搜索用时 62 毫秒
1.
In this paper, we present a structure for obtaining the exact eigenfunctions and eigenvalues of the Jaynes–Cummings model(JCM) without the rotating wave approximation(RWA). We study the evolution of the system in the strong coupling region using the time evolution operator without RWA. The entanglement of the system without RWA is investigated using the Von Neumann entropy as an entanglement measure. It is interesting that in the weak coupling regime, the population of the atomic levels and Von Neumann entropy without RWA model shows a good agreement with the RWA whereas in strong coupling domain, the results of these two models are quite different. 相似文献
2.
In this paper, the entanglement dynamics of a double
two-photon Jaynes--Cummings model with Kerr-like medium is
investigated. It is shown that initial entanglement has an
interesting subsequent time evolution, including the so-called
entanglement sudden death effect. It is also shown analytically that
the Kerr-like medium can repress entanglement sudden death and enhance
the degree of atom--atom entanglement. A more interesting fact is
that the Kerr effect is more obvious when each of the two cavities
with have the Kerr-like medium than only one of them with the Kerr-like medium. 相似文献
3.
A system consisting of two atoms interacting with a
two-mode vacuum is considered, where each atom is resonant with the
two cavity modes through two different competing transitions. The
effect of mode--mode competition on the atom--atom entanglement is
investigated. We find that the entanglement between the two atoms
can be induced by the mode--mode competition. For the initial atomic
state |\varPsi(0)\rangle, whether the atoms are initially
separated or entangled, a large or even maximal entanglement between
them can be obtained periodically by introducing the mode--mode
competition. For the initial atomic state |\varPhi(0)\rangle, the
strong mode--mode competition can prevent the two atoms entangled
initially from suffering entanglement sudden death; besides, it
makes them in a more stable and longer-lived entanglement than in
the non-competition case. 相似文献
4.
The influences of dipole--dipole interaction and detuning on the sudden death of entanglement between two atoms in the Tavis--Cummings model 下载免费PDF全文
The influences of dipole--dipole interaction and detuning on the
entanglement between two atoms with different initial tripartite
entangled W-like states in the Tavis--Cummings model have been
investigated by means of Wootters' concurrence, respectively. The
results show that the entanglement between the two atoms can be
enhanced via appropriately tuning the strength of dipole--dipole
interaction of two atoms or the detunings between atom and cavity,
and the so-called sudden death effect can be weakened
simultaneously. 相似文献
5.
M MOHAMMADI 《Pramana》2012,78(5):767-778
In this paper, the quantum properties of a two-level atom and the cavity-field in the Jaynes?CCummings model with the gravity beyond the rotating wave approximation are investigated. For this purpose, by solving the Schr?dinger equation in the interaction picture, the evolving state of the system is found by which the influence of the counter-rotating terms on the dynamical behaviour of atomic population inversion and the probability distribution of the cavity-field as quantum properties is explored. The results in the atom?Cfield system beyond the rotating wave approximation with the gravity show that the quantum properties are not completely suppressed under certain conditions. 相似文献
6.
7.
We propose a method to construct new quantum integrable models. As an example, we construct an integrable anisotropic quantum spin chain which includes the nearest-neighbor, next-nearestneighbor and chiral three-spin couplings. It is shown that the boundary fields can enhance the anisotropy of the first and last bonds, and can induce the Dzyloshinsky–Moriya interactions along the z-direction at the boundaries. By using the algebraic Bethe ansatz, we obtain the exact solution of the system. The energy spectrum of the system and the associated Bethe ansatz equations are given explicitly. The method provided in this paper is universal and can be applied to constructing other exactly solvable models with certain interesting interactions. 相似文献
8.
9.
Exact solution of the Gaudin model with Dzyaloshinsky–Moriya and Kaplan–Shekhtman–Entin–Wohlman–Aharony interactions 下载免费PDF全文
《中国物理 B》2021,30(5):50201-050201
We study the exact solution of the Gaudin model with Dzyaloshinsky–Moriya and Kaplan–Shekhtman–Entin–Wohlman–Aharony interactions. The energy and Bethe ansatz equations of the Gaudin model can be obtained via the off-diagonal Bethe ansatz method. Based on the off-diagonal Bethe ansatz solutions, we construct the Bethe states of the inhomogeneous X X X Heisenberg spin chain with the generic open boundaries. By taking a quasi-classical limit, we give explicit closed-form expression of the Bethe states of the Gaudin model. From the numerical simulations for the small-size system, it is shown that some Bethe roots go to infinity when the Gaudin model recovers the U(1) symmetry. Furthermore,it is found that the contribution of those Bethe roots to the Bethe states is a nonzero constant. This fact enables us to recover the Bethe states of the Gaudin model with the U(1) symmetry. These results provide a basis for the further study of the thermodynamic limit, correlation functions, and quantum dynamics of the Gaudin model. 相似文献
10.
Exact solution of the one-dimensional Klein-Gordon equation with scalar and vector linear potentials in the presence of a minimal length 下载免费PDF全文
Using the momentum space representation, we solve the Klein-Gordon equation in one spatial dimension for the case of mixed scalar and vector linear potentials in the context of deformed quantum mechanics characterized by a finite minimal uncertainty in position. The expressions of bound state energies and the associated wave functions are exactly obtained. 相似文献
11.
Extending the double Jaynes--Cummings model to a more
complicated case where the mode--mode competition is considered, we
investigate the entanglement character of two isolated atoms by
means of concurrence, and discuss the dependence of atom--atom
entanglement on the different initial state and the relative
coupling strength between the atom and the corresponding cavity
field. The results show that the amplitude and the period of the
atom--atom entanglement evolution can be controlled by the choice of
initial state and relative coupling strength, respectively. We find
that the phenomenon of entanglement sudden death (ESD) is sensitive
to the initial conditions. The length of the time interval for
zero entanglement depends not only on the initial degree of
entanglement between two atoms but also on the relative coupling
strength of atom--field interaction. The ESD effect can be weakened
by enhancing the mode--mode competition between the three- and
single-photon processes. 相似文献
12.
Stig Stenholm 《Optics Communications》1981,36(1):75-78
The dynamics of the Jaynes—Cummings model is solved completely in a Bargmann representation. The result is the power series obtained earlier in the occupation number representation; a suggestive reformulation of the problem in terms of a simple partial differential equation ensues. 相似文献
13.
本文研究了频率随时间变化的光场对双J-C模型中原子--原子纠缠的动力学调控, 主要讨论了光场频率随时间作正弦变化和脉冲变化两种典型情况下, 原子--原子纠缠度随时间的演化特性. 当光场频率随时间作正弦变化时, 原子--原子纠缠度演化的周期、振幅与光场频率调制的振幅有关, 并随着调制振幅的增强而减小. 光场频率的正弦调制和脉冲调制均能使光场与原子的相互作用模式在共振和非共振之间发生变化, 直接影响原子--原子纠缠度的演化规律. 通过光场频率的调制可以实现原子--原子纠缠度的提高与稳定, 避免ESD现象的出现, 从而达到动态调控原子--原子纠缠的目的. 相似文献
14.
A system consisting of two different atoms interacting with a two-mode vacuum, where each atom is resonant only with one cavity mode, is considered. The effects of dipole-dipole (dd) interaction between two atoms on the atom-atom entanglement and mode--mode entanglement are investigated. For a weak dd interaction, when the atoms are initially separable, the entanglement between them can be induced by the dd interaction, and the entanglement transfer between the atoms and the modes occurs efficiently; when the atoms are initially entangled, the entanglement transfer is almost not influenced by the dd interaction. However, for a strong dd interaction, it is difficult to transfer the entanglement from the atoms to the modes, but the atom-atom entanglement can be maintained when the atoms are initially entangled. 相似文献
15.
In this paper the so-called sudden death effect of entanglement is
investigated in a quantum model. The results show that one can
expect the resurrection of the original entanglement to occur in a
periodic way following each sudden death event. The length of the
time interval for the zero entanglement depends not only on the
degree of entanglement of the initial state but also on the initial
state. 相似文献
16.
Optical bistability for two-level atomic system in a ring cavity is investigated outside the rotating wave approximation (RWA) using non-autonomous Maxwell-Bloch equations with Fourier decomposition up to first harmonic. The first harmonic output field component exhibits reversed or closed loop bistability simultaneously with the usual (anti-clockwise) bistability in the fundamental field component. 相似文献
17.
Q. Xu 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2009,51(3):387-392
The effects of the non-rotating wave approximation (non-RWA) on the
spontaneous emission of a V-type three-level atom are studied, where the
excited states are coupled to a common ground state by a weak laser field
and the upper-level doublet is driven by a strong microwave field. When the
non-RWA is applied to the interaction of the atom with the microwave field,
for some values of the parameters involved, the spontaneous emission
spectrum is comprised of a central peak and a series of sidebands with a
constant spacing of the microwave frequency, and the central peak and/or
sidebands can be split into two components. The physical interpretation of
the spectral characteristics is given in light of the dressed states. 相似文献