共查询到17条相似文献,搜索用时 768 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.
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
4.
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
5.
LIUXiao-Juan FANGMao-Fa ZHOUQing-Ping 《中国物理快报》2004,21(6):1071-1074
We study the entropy and the entanglement of an electromagnetically induced transparency system. The quantumentanglement between the atom and the two quantized laser fields is discussed by using quantum reduced entropyand that between the two quantized laser fields by using quantum relative entropy. We also examine whetherinfluences of EIT on entropy and quantum entanglement of the system considered occur or not. Our resultsshow that the minimum value of the atomic reduced entropy may be regarded as an entropy criterion on theelectromagnetically induced transparency occurring. 相似文献
6.
We investigate the entanglement in a system of two coupling atoms
interacting with a single-mode field
by means of quantum information entropy theory.
The quantum entanglement between the two atoms and the coherent field is discussed by using
the quantum reduced entropy,
and the entanglement between the two coupling atoms is also investigated
by using the quantum relative entropy.
In addition, the influences of the atomic dipole--dipole interaction
intensity and
the average photon number of the coherent field on the degree of the entanglement is examined.
The results show that the evolution of the degree of entanglement between the two atoms
and the field is just opposite to that of the degree of entanglement between the two atoms.
And the properties of the quantum entanglement in the system rely on the
atomic dipole--dipole
interaction and the average photon number of the coherent field. 相似文献
7.
Single-atom entropy squeezing and quantum entanglement in Tavis--Cummings model with atomic motion 下载免费PDF全文
We examine the single-atom entropy squeezing and the atom-field entanglement in a system of two moving twolevel atoms interacting with a single-mode coherent field in a lossless resonant cavity.Our numerical calculations indicate that the squeezing period,the squeezing time and the maximal squeezing can be controlled by appropriately choosing the atomic motion and the field-mode structure.The atomic motion leads to a periodical time evolution of entanglement between the two-atom and the field.Moreover,there exists corresponding relation between the time evolution properties of the atomic entropy squeezing and that of the entanglement between the two atoms and the field. 相似文献
8.
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
9.
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 nonlinearties of the two-mode fields.we derive a Raman-coupled effective Hamiltonian by a unitary transformation,evaluated perturbatively in coupling constants.We use the quantum entropy to measure the degree of entanglement in the time development of an effective two-level atom interacting with two-mode nonlinear-coherent states.The results show that the nolinearity effect yields the superstructure of atomic Radi oscillations and the effect of the Stark shift changes the quasiperiod of the field entropy evolution and entanglement between the particle and the field.A possible experimental test of a new effect is proposed. 相似文献
10.
The entanglement dynamics between an isolated atom and a moving atom
interacting with a cavity field is investigated. The results show
that there appears sudden death of entanglement between the isolated
atom and the moving atom and that the time of entanglement sudden
death (ESD) is independent of the initial state of the system. It is
interesting that the isolated atom can also entangle with a cavity
field, though they do not interact with each other originally, which
stems from the fact that the entanglement between the isolated atom
and the moving atom may turn into the entanglement between the
isolated atom and the cavity. 相似文献
11.
《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
12.
Entangled states in the two-mode coherent fields interacting with a two-level atom 总被引:2,自引:0,他引:2 下载免费PDF全文
We investigate the entanglement properties of the two-mode coherent fields interacting with a two-level atom via the two-photon transition. We discuss the quantum entanglement between the two-mode coherent fields and the two-level atom by using the quantum reduced entropy and that between the two-mode coherent fields by using the quantum relative entropy. We also examine the influences of the initial states of the atom and the two-mode coherent fields on the quantum entanglement of the system. Our results show that three types of entangled states can be prepared via the two-mode coherent fields interacting with a two-level atom and choosing appropriately the initial-state parameters of the system. 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.
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
15.
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
16.
17.
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