共查询到20条相似文献,搜索用时 31 毫秒
1.
For the Raman interaction between an atom and a two-mode cavity field prepared in the state |01> or |10> , the atom and the field can be disentangled periodically. Such a property of Raman atom-field interaction allows the full entanglement transfer among many atoms and bimodal cavities. In the calculations, each atom is assumed to interact with its own cavity at a different time and so non-identical atoms can be treated conveniently. Entanglement sudden death is discussed too. Though atom-field interaction greatly changes the values of the concurrence for two atoms, configuration of the concurrence is almost not affected. When there is entanglement sudden death, atoms and cavities can still be entangled with one another. However, full entanglement transfer cannot be achieved for such systems with Raman atom-field interaction. 相似文献
2.
The entanglement properties of two entangled atoms interacting with the field under intensity-dependent coupling are studied in detail. It is found that the degree of entanglement between the two atoms changes periodically and undergoes the entanglement sudden death (ESD) and sudden birth at some time. The entanglement properties between the field and the atom inside the cavity are dependent on the photon number. Most interestingly, the entanglement between the field and the atom in the field is influenced significantly by manipulating the atom outside the field. 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 entanglement dynamics of system, where atoms A and B interact with single mode cavity fields a and b respectively, is studied. The interaction between atom A and cavity a may be described by using the typical Jaynes Cummings model, while that between the atom B and cavity b filled with a Kerr medium is of a two-photon process. For a certain initial atom entanglement state, there is an entanglement sudden death effect between the two atoms. The Kerr medium in the cavity b can effectively prevent the undesirable entanglement sudden death from occurring. Also, from the viewpoint of the population dynamics, we discuss why the Kerr medium can do so. 相似文献
5.
考虑将初始处于纠缠态的一个原子注入处于Fock态的单模腔中,并且原子与光场发生共振相互作用的情况,采用Negativity熵来描述两子系统间的纠缠,运用数值计算方法研究了腔内原子与光场间的纠缠特性.通过是否进行原子态选择性测量情况下,对腔内原子与光场间的纠缠特性的比较,讨论了腔外原子的测量对纠缠特性的影响.研究结果表明... 相似文献
6.
Entanglement swapping between atom and cavity and generation of entangled state of cavity fields 下载免费PDF全文
This paper proposes a scheme where entanglement swapping between atom and cavity can
be realized. \Lambda -type three-level atoms interacting resonantly with
cavity field are considered. By detecting atom and cavity field, it
realizes entanglement swapping between atom and cavity. It uses the technique
of entanglement swapping to generate an entangled state of two cavity fields
by measuring on atoms. It discusses the experimental feasibility of
the proposed scheme
and application of entangled state of cavity fields. 相似文献
7.
Jiao Chen X. L. Huang H. Y. Sun X. X. Yi 《International Journal of Theoretical Physics》2009,48(5):1405-1414
In this paper we study the influence of cavity decay on the atomic tunneling and entanglement dynamics in a cavity QED system.
The system consists of an atom in a double-well potential and a cavity. The results show that the cavity decay affects significantly
the tunneling and the entanglement dynamics. The tunneling behaves as a damping-oscillating function of time in this case,
while the entanglement shared between the internal and external degree of freedom of the atom exhibits the so-called entanglement
sudden death (ESD). 相似文献
8.
考虑一个运动的二能级原子与单模热光场经由多光子过程相互作用, 利用量子约化熵理论研究原子与场之间的熵交换、用Concurrence量度原子与场之间的纠缠, 讨论原子初态、原子运动、热场平均光子数以及跃迁光子数对熵交换和纠缠的影响. 结果表明: 考虑原子运动时, 原子和光场熵变呈现周期性, 且发生熵交换现象; 与热光场的相互作用导致运动原子与场纠缠, 多光子过程有利于纠缠加强. 在原子和光场熵变均为零处, 纠缠也为零. 相似文献
9.
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
10.
Optimal entropy squeezing sudden generation and its control for an effective two-level moving atom entanglement with the two-mode coherent fields 下载免费PDF全文
From the viewpoint of quantum information, this paper proposes a
concept and a definition of the atomic optimal entropy squeezing
sudden generation (AOESSG) for the system of an effective two-level
moving atom which entangles with the two-mode coherent fields. It
also researches the relationship between the AOESSG and
entanglement sudden death of the atom-fields, and discusses the
influences of atomic initial state on the AOESSG and obtains the
system parameter which controls the AOESSG. 相似文献
11.
12.
Hünkar Kayhan 《理论物理通讯》2011,56(3):487-489
We investigate the properties of entanglement between an isolated atom and a Jaynes-Cummings atom in the presence of transient effects. These effects are due to the modulation of the atom-field coupling whose explicit time-dependence is considered for the case of the linear sweep. We show that the sudden death of entanglement can be controlled by the transient effects. These effects can suppress the sudden death of entanglement in time. 相似文献
13.
研究了初始处于GHZ态的三个两能级原子与双模腔场相互作用系统的纠缠动力学特性,得到了并发度和线性熵的解析表达式.讨论了腔场初始纠缠度对腔内两原子之间纠缠的影响,对其余子系统求迹后结果表明腔内两原子之间的纠缠出现突然产生现象,腔内两原子之间产生纠缠的阈值时间和最大值依赖于双模腔场初始纠缠度;并且发现腔内两原子子系统和腔外原子与场子系统之间在整个的时间演化过程中一直保持着纠缠状态. 相似文献
14.
15.
Preparation and control of atomic optimal entropy squeezing states for a moving two-level atom under control of the two-mode squeezing vacuum fields 下载免费PDF全文
From the viewpoint of quantum information,this paper studies preparation and control of atomic optimal entropy squeezing states(AOESS) for a moving two-level atom under control of the two-mode squeezing vacuum fields.Necessary conditions of preparation of the AOESS are analysed,and numerical verification of the AOESS is finished.It shows that the AOESS can be prepared by controlling the time of the atom interaction with the field,cutting the entanglement between the atom and field,and adjusting squeezing factor of the field.An atomic optimal entropy squeezing sudden generation in different components can alternately be realized by controlling the field-mode structure parameter. 相似文献
16.
17.
闫丽 《原子与分子物理学报》2019,36(6)
本文将两个二能级原子注入一个腔中,用共生纠缠的方法来度量两原子之间的纠缠并推出它们之间的量子失协,还给出了原子与环境之间的共生纠缠与量子失协的计算公式,讨论了原子自发衰变率的变化对量子纠缠及失协的影响,及不同的初始状态情况下,纠缠及失协随原子距离的演化情况。结果表明:原子自发衰变率减小,原子与环境之间的量子纠缠及失协增加;选择不同的初态,可以控制原子间出现纠缠死亡的现象或量子失协为零的状态。 相似文献
18.
闫丽 《原子与分子物理学报》2017,34(4):716-721
本文将两个二能级原子注入一个腔中,用共生纠缠的方法来度量两原子之间的纠缠并推出它们之间的量子失协,还给出了原子与环境之间的共生纠缠与量子失协的计算公式,讨论了原子自发衰变率的变化对量子纠缠及失协的影响,及不同的初始状态情况下,纠缠及失协随原子距离的演化情况.结果表明:原子自发衰变率减小,原子与环境之间的量子纠缠及失协增加;选择不同的初态,可以控制原子间出现纠缠死亡的现象或量子失协为零的状态. 相似文献
19.
闫丽 《原子与分子物理学报》2018,35(6)
本文将两个二能级原子注入一个腔中,用共生纠缠的方法来度量两原子之间的纠缠并推出它们之间的量子失协,还给出了原子与环境之间的共生纠缠与量子失协的计算公式,讨论了原子自发衰变率的变化对量子纠缠及失协的影响,及不同的初始状态情况下,纠缠及失协随原子距离的演化情况。结果表明:原子自发衰变率减小,原子与环境之间的量子纠缠及失协增加;选择不同的初态,可以控制原子间出现纠缠死亡的现象或量子失协为零的状态。 相似文献
20.
S. J. Akhtarshenas M. Khezrian 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2010,57(2):271-279
In this paper, we investigate the entanglement dynamics anddecoherence in the interacting system of a strongly driventwo-level atom and a single mode vacuum field in the presence ofdissipation for the cavity field. Starting with an initial productstate with the atom in a general pure state and the field in avacuum state, we show that the final density matrix is supportedon \({\mathbb C}^2\otimes{\mathbb C}^2\) space, and therefore, theconcurrence can be used as a measure of entanglement between theatom and the field. The influences of the cavity decay on thequantum entanglement of the system are also discussed. We alsoexamine the Bell-CHSH violation between the atom and the field andshow that there are entangled states for which the Bell-BCSHinequality is not violated. Using the above system as a quantumchannel, we also investigate the quantum teleportation of ageneric qubit state and also a two-qubit entangled state, and showthat in both cases the atom-field entangled state can be useful toteleport an unknown state with fidelity better than any classicalchannel. 相似文献