共查询到20条相似文献,搜索用时 46 毫秒
1.
Preparation and control of entangled states in the two-mode coherent fields interacting with a moving atom via two-photon process 下载免费PDF全文
We investigate the preparation and the control of entangled
states in a system with the two-mode coherent fields interacting
with a moving two-level atom via the two-photon transition. We
discuss entanglement properties between the two-mode coherent
fields and a moving two-level atom by using the quantum reduced
entropy, and those between the two-mode coherent fields by using
the quantum relative entropy. In addition, we examine the
influences of the atomic motion and field-mode structure
parameter $p$ on the quantum entanglement of the system. Our
results show that the period and the duration of the prepared
maximal atom-field entangled states and the frequency of maximal
two-mode field entangled states can be controlled, and that a
sustained entangled state of the two-mode field, which is
independent of atomic motion and the evolution time, can be
obtained, by choosing appropriately the parameters of atomic
motion, field-mode structure, initial state and interaction time
of the system. 相似文献
2.
Quantum entanglement between the two-mode fields and atomic entropy squeezing in the system of a moving atom interacting with two-mode entangled coherent field 下载免费PDF全文
This paper investigates the entropy squeezing of a moving two-level
atom interacting with the two-mode entangled coherent field via
two-photon transition by using an entropic uncertainty relation and the
degree of entanglement between the two-mode fields by using quantum
relative entropy. The results obtained from numerical calculation
indicate that the squeezed period, the duration of entropy squeezing
and the maximal squeezing can be controlled by appropriately
choosing the intensity of the light field, the atomic motion and the
field-mode structure. The atomic motion leads to the periodic
recovery of the initial maximal degree of entanglement between the
two-mode fields. Moreover, there exists a corresponding relation
between the time evolution properties of the atomic entropy
squeezing and those of the entanglement between the two-mode fields. 相似文献
3.
Considering a two-level atom interacting with the competing two-mode field, this paper investigates the entanglement between the two-level atom and the two-mode field by using the quantum reduced entropy, and that between the two-mode field by using the quantum relative entropy of entanglement. It shows that the two kinds of entanglement are dependent on the relative coupling strength of atom-field and the atomic distribution, and exhibit the periodical evolution. The maximal atom-field entanglement state can be prepared via the appropriate selection of system parameters and interaction time. 相似文献
4.
Based on the quantum information theory, this paper has investigated
the entanglement properties of a system which is composed of the two
entangled two-level atoms interacting with the two-mode entangled
coherent fields. The influences of the strength of light field and
the two parameters of entanglement between the two-mode fields on
the field entropy and on the negative eigenvalues of partial
transposition of density matrix are discussed by using numerical
calculations. The result shows that the entanglement properties in a
system of a pairwise entangled states can be controlled by
appropriately choosing the two parameters of entanglement between
the two-mode entangled coherent fields and the strength of two light
fields respectively. 相似文献
5.
Quantum entanglement in the system of two two-level atoms interacting with a single-mode vacuum field 总被引:5,自引:0,他引:5 下载免费PDF全文
The entanglement properties of the system of two two-level atoms interacting with a single-mode vacuum field are explored. The quantum entanglement between two two-level atoms and a single-mode vacuum field is investigated by using the quantum reduced entropy; the quantum entanglement between two two-level atoms, and that between a single two-level atom and a single-mode vacuum field are studied in terms of the quantum relative entropy. The influences of the atomic dipole--dipole interaction on the quantum entanglement of the system are also discussed. Our results show that three entangled states of two atoms--field, atom--atom, and atom--field can be prepared via two two-level atoms interacting with a single-mode vacuum field. 相似文献
6.
LIUXiao-Juan FANGMao-Fa 《理论物理通讯》2004,42(1):103-109
From a quantum information point of view we investigate the entropy squeezing properties for a two-level atom interacting with the two-mode coherent fields via the two-photon transition. We discuss the influences of the initial state of the system on the atomic information entropy squeezing. Our results show that the squeezed component number, squeezed direction, and time of the information entropy squeezing can be controlled by choosing atomic distribution angle, the relative phase between the atom and the two-mode field, and the difference of the average photon number of the two field modes, respectively. Quantum information entropy is a remarkable precision measure for the atomic squeezing. 相似文献
7.
LIU Xiao-Juan FANG Mao-Fa 《理论物理通讯》2004,42(7)
From a quantum information point of view we investigate the entropy squeezing properties for a two-level atom interacting with the two-mode coherent fields via the two-photon transition. We discuss the influences of the initial state of the system on the atomic information entropy squeezing. Our results show that the squeezed component number,squeezed direction, and time of the information entropy squeezing can be controlled by choosing atomic distribution angle,the relative phase between the atom and the two-mode field, and the difference of the average photon number of the two field modes, respectively. Quantum information entropy is a remarkable precision measure for the atomic squeezing. 相似文献
8.
Quantum entanglement in the system of a moving V-type three-level atom interacting with the SU(1,1)-related coherent fields 下载免费PDF全文
In a system with a moving V-type three-level atom interacting with
the SU(1,1)-related coherent fields,
we investigate the entanglement between the moving three-level atom
and the SU(1,1)-related coherent fields by
using the quantum-reduced entropy, and that
between the SU(1,1)-related
coherent fields by using the quantum relative
entropy of entanglement. It is shown that the two kinds of entanglement
are dependent on the atomic motion and
exhibit the periodic evolution with a
period of 2π/p. The maximal atom--field qutrit entanglement
state can be prepared, and the entanglement preservation
of the SU(1,1)-related coherent fields
can be realized in the interacting process
via the appropriate selection of system
parameters and interaction time. 相似文献
9.
10.
通过求解系统的Milburn方程,研究了两能级原子与双模SU(1,1)相干态光场发生相互作用系统中,原子与场的纠缠及双模SU(1,1)相干态场的模间纠缠随时间的演化问题,讨论了内禀退相干、双模光子数差等对纠缠度的影响.结果表明,存在内禀退相干时,随着时间的演化,场-原子纠缠逐渐减小到一个确定值,而模间纠缠逐渐增大到一个确定值,两者演化的最终值只取决于双模光子数差和平均光子数,而与内禀退相干因子无关.
关键词:
Milburn理论
SU(1
1)相干态
量子约化熵
量子相对熵 相似文献
11.
根据大失谐条件下原子-腔场相互作用的特点,讨论了一个制备纠缠压缩态的方法,提出了一个利用两能级原子与腔场相互作用实现纠缠压缩态纠缠浓缩的方案。在这个方案中,两束具有相同振幅但有着 相位差的压缩光 和 构成的纠缠态光场被用来作为量子信道。通过利用两能级原子与腔场的相互作用以及两模正交态测量实现了这个纠缠浓缩的过程。结果表明:对于纠缠压缩态,无论其初始的纠缠是多么微弱,利用这种方法总有一定的几率可以从部分纠缠态中提取出最大纠缠态。 相似文献
12.
研究的系统为SU(1, 1)相干态和玻色-爱因斯坦凝聚体相互作用体系,在双光子跃迁过程中,分别用量子约化熵和量子相对熵研究了该系统中的SU(1, 1)相干态与凝聚体间的纠缠以及SU(1, 1)相干态的模间纠缠,分析了光场初始压缩因子、原子间相互作用对场-凝聚体间纠缠和模间纠缠的影响。 相似文献
13.
SU(1,1)相干态与玻色-爱因斯坦凝聚相互作用系统中的量子纠缠 总被引:4,自引:4,他引:0
研究的系统为SU(1, 1)相干态和玻色-爱因斯坦凝聚体相互作用体系,在双光子跃迁过程中,分别用量子约化熵和量子相对熵研究了该系统中的SU(1, 1)相干态与凝聚体间的纠缠以及SU(1, 1)相干态的模间纠缠,分析了光场初始压缩因子、原子间相互作用对场-凝聚体间纠缠和模间纠缠的影响。 相似文献
14.
15.
In this communication, two-mode nonlinear coherent states are reviewed and special cases are given.Starting from a three-level atom coupled to two modes of radiation with any form of nonlinearities of the two-modefields, we derive a Raman-coupled effective Hamiltonian by a unitary transformation, evaluated perturbatively in couplingconstants. We use the quantum entropy to measure the degree of entanglement in the time development of an effectivetwo-level atom interacting with two-mode nonlinear-coherent states. The results show that the nonlinearity effect yieldsthe superstructure of atomic Rabi oscillations and the effect of the Stark shift changes the quasiperiod of the field entropyevolution and entanglement between the particle and the field. A possible experimental test of a new effect is proposed. 相似文献
16.
《Physica A》2006,365(2):351-359
The entanglement properties of the SU(1, 1)-related coherent fields interacting with a moving atom via the two-photon transition are investigated. We discuss the quantum entanglement between the SU(1, 1)-related coherent fields and the moving atom by using the quantum reduced entropy and that between the SU(1, 1)-related coherent fields by using the quantum relative entropy. It is shown that we can obtain the maximal entangled state between the fields and the moving atom and the high degree of entanglement between the SU(1, 1)-related coherent fields can be preserved for some choiced system parameters. 相似文献
17.
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
18.
双模纠缠相干光场控制下双光子过程中有效二能级原子的信息熵压缩 总被引:1,自引:1,他引:0
根据量子信息理论,研究了与双模纠缠相干场相互作用双光子过程中有效二能级原子的信息熵压缩.讨论了场的初态对信息熵压缩的因影响,并且比较了分别从基于信息熵测不准关系和海森堡测不准关系出发得出的结果.结果表明:信息熵压缩的稳定周期性、压缩方向分别由场的平均光子数和方向角控制,场的纠缠度对信息熵压缩不产生影响.信息熵压缩实现了对原子压缩效应的高灵敏量度. 相似文献
19.
Entropy evolvement properties in a system of Schrodinger cat state light field interacting with two entangled atoms 下载免费PDF全文
The field entropy can be regarded as a measurement of the degree of
entanglement between the light field and the atoms of a system which is
composed of two-level atoms initially in an entangled state interacting with the Schr\"{o}dinger cat state. The influences of the strength of light field and the phase angle between the two coherent states on the field entropy are discussed by using numerical calculations. The result shows that when the strength of light field is large enough the field entropy is not zero and the degrees of entanglement between the atoms and the three different states of the light fields are equal. When the strength of the light field is small, the degree of entanglement is maximum in a system of the two entangled atoms interacting with an odd coherent state; it is intermediate for a system of the two entangled atoms interacting with the Yurke--Stoler coherent state, and it is minimum in a system of the two entangled atoms interacting with an even coherent state. 相似文献