共查询到20条相似文献,搜索用时 78 毫秒
1.
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
2.
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
3.
The entropy squeezing properties for a two-level
atom interacting with a two-mode field via two different competing transitions
are investigated from a quantum information point of view. The influences
of the initial state of the system and the relative coupling strength between the atom and the field
on the atomic information entropy squeezing are discussed. Our results show that
the squeezed direction and the frequency of the information entropy squeezing
can be controlled by choosing the phase of the atom dipole and the relative competing
strength of atom-field, respectively.
We find that, under the same condition, no atomic variance squeezing is predicted from the
HUR while optimal entropy squeezing is obtained from the EUR, so the quantum information
entropy is a remarkable precision measure for the atomic squeezing
in the considered system. 相似文献
4.
Entropy squeezing for a two-level atom in the Jaynes-Cummings model with an intensity-depend coupling 总被引:1,自引:0,他引:1 下载免费PDF全文
We study the squeezing for a two-level atom in the Jaynes-Cummings model with intensity-dependent coupling using quantum information entropy, and examine the influences of the initial state of the system on the squeezed component number and direction of the information entropy squeezing. Our results show that, the squeezed component number depends on the atomic initial distribution angle, while the squeezed direction is determined by both the phases of the atom and the field for the information entropy squeezing. Quantum information entropy is shown to be a remarkable precision measure for atomic squeezing. 相似文献
5.
运用量子信息熵理论研究了双光子过程中任意初态二能级原子与相干场相互作用的信息熵压缩,讨论了系统初态对原子信息熵压缩的影响. 并且比较了分别从基于信息熵不确定关系和海森伯不确定关系出发得出的结果. 结果表明通过选择适当初始的原子分布角,原子的混合度和相干场的位相角,可以分别控制原子信息熵压缩的偶极矩分量数、压缩频率、压缩幅度和压缩方向. 当原子反转为零时,基于海森堡不确定关系的方差压缩定义不再有效,而信息熵压缩实现了对原子压缩效应的高灵敏量度.
关键词:
二能级原子
双光子过程
信息熵压缩
方差压缩 相似文献
6.
与二项式光场相互作用的运动原子熵压缩 总被引:2,自引:2,他引:0
运用量子信息熵理论,研究了二项式光场与运动二能级原子相互作用过程中运动原子的信息熵压缩。讨论了不同的原子初态和场的有关参数对原子信息熵压缩的影响。结果表明:选择原子初态、场模结构、场调节参数及原子运动速度可以调控原子信息熵的压缩方向、偶极矩分量值和压缩周期;适当的选择参数可得到持续性的原子信息熵压缩。 相似文献
7.
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
8.
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. 在强场条件下, 场的纠缠度对信息熵压缩不产生影响。当原子反转为零时,基于海森堡测不准关系的方差压缩定义不再有效, 而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
9.
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
10.
Entropy squeezing of a moving atom and control of noise of the quantum mechanical channel via the two-photon process 下载免费PDF全文
Based on the quantum information theory, we have investigated the
entropy squeezing of a moving two-level atom interacting with the
coherent field via the quantum mechanical channel of the two-photon
process. The results are compared with those of atomic squeezing
based on the Heisenberg uncertainty relation. The influences of the
atomic motion and field-mode structure parameter on the atomic
entropy squeezing and on the control of noise of the quantum
mechanical channel via the two-photon process are examined. Our
results show that the squeezed period, duration of optimal entropy
squeezing of a two-level atom and the noise of the quantum mechanical
channel can be controlled by appropriately choosing the atomic motion
and the field-mode structure parameter, respectively. The quantum
mechanical channel of two-photon process is an ideal channel for
quantum information (atomic quantum state) transmission. Quantum
information entropy is a remarkably accurate measure of the atomic
squeezing. 相似文献
11.
与量子光场相互作用的运动原子的熵压缩 总被引:9,自引:1,他引:8
运用量子信息熵理论,研究了与量子光场相互作用的二能级运动原子的熵压缩,讨论了原子运动和场模结构对原子熵压缩的影响,并且比较了分别从基于信息熵测不准关系和海森伯测不准关系出发得出的结果,表明原子的运动导致了原子熵压缩的周期性演化;随着场模结构参量的增大,熵压缩的演化周期缩短,压缩时间延长;选择适当的系统参量,运动原子能够呈现长时间的持续熵压缩效应。当原子反转为零时,基于海伯堡测不准关系的方差压缩定义不再有效,而熵压缩实现了对原子压缩效应的高灵敏量度。 相似文献
12.
Entropy squeezing for a two-level atom in two-mode Raman coupled model with intrinsic decoherence 总被引:1,自引:0,他引:1 下载免费PDF全文
In this paper, we investigate the entropy squeezing for a two-level
atom interacting with two quantized fields through Raman coupling.
We obtain the dynamical evolution of the total system under the
influence of intrinsic decoherence when the two quantized fields are
prepared in a two-mode squeezing vacuum state initially. The effects
of the field squeezing factor, the two-level atomic transition
frequency, the second field frequency and the intrinsic decoherence
on the entropy squeezing are discussed. Without intrinsic
decoherence, the increase of field squeezing factor can break the
entropy squeezing. The two-level atomic transition frequency changes
only the period of oscillation but not the strength of entropy
squeezing. The influence of the second field frequency is
complicated. With the intrinsic decoherence taken into
consideration, the results show that the stronger the intrinsic
decoherence is, the more quickly the entropy squeezing will
disappear. The increase of the atomic transition frequency can
hasten the disappearance of entropy squeezing. 相似文献
13.
利用全量子理论,研究了多光子Jaynes-Cummings模型中与Glauber-Lachs态相互作用的混合态原子的信息熵压缩。讨论了相干平均光子数、热平均光子数、跃迁光子数、原子初态参量对原子信息熵压缩的影响。结果表明原子信息熵 分量没有熵压缩性质;相干平均光子数取值适当时,原子信息熵 分量呈现熵压缩效应;热平均光子数、跃迁光子数会破坏原子信息熵 分量的熵压缩效应;原子初态参量对原子信息熵 分量能否呈现熵压缩效应没有决定性作用;伴随双光子跃迁时,原子的熵压缩因子的时间演化曲线呈现周期性。 相似文献
14.
15.
与关联双模辐射场作用的级联三能级
原子的偶极压缩效应 总被引:16,自引:6,他引:10
研究了与关联双模压缩真空场作用的级联三能级原子的偶极压缩效应。通过数值计算,讨论 了初始压缩光场的压缩参数、单光子失谐量以及原子-光场耦合强度对原子偶极压缩的影响 。 相似文献
16.
为了研究三光子过程中原子与相干态耦合量子体系信息熵压缩随时间演化规律及原子最佳信息熵压缩态的制备,我们采用全量子理论,推导出运动原子与单模简并三光子依赖强度耦合量子体系的精确解;理论上给出制备原子最佳信息熵压缩态的充分及必要条件,并进行了数值模拟验证.研究结果表明:控制相干态场与原子作用时间,切断相干态场与原子的纠缠,选择二能级原子处于等权重相干叠加态,适当选取相干态场与原子的初始位相,可以制备出原子最佳量子信息熵压缩态;调节光腔中场模结构参量,能够得到连续的量子信息熵压缩态.该研究结果在多光子过程低噪声量子信息处理中具有一定意义. 相似文献
17.
Mahmoud Abdel-Aty 《理论物理通讯》2002,37(6)
We investigate the entropy squeezing of the nonlinear k-quantum JC model. A definition of squeezing is presented for this system based on the quantum information theory. The utility of the definition is illustrated by examining squeezing in the information entropy of a nonlinear k-quantum two-level atom. The influence of the atomic coherence and the detuning parameter on the properties of the information entropy and squeezing of the atomic variables is examined. 相似文献
18.
为了研究三光子过程中原子与相干态耦合量子体系信息熵压缩随时间演化规律及原子最佳信息熵压缩态的制备,我们采用全量子理论,推导出运动原子与单模简并三光子依赖强度耦合量子体系的精确解;理论上给出制备原子最佳信息熵压缩态的充分及必要条件,并进行了数值模拟验证。研究结果表明:控制相干态场与原子作用时间,切断相干态场与原子的纠缠,选择二能级原子处于等权重相干叠加态,适当选取相干态场与原子的初始位相,可以制备出原子最佳量子信息熵压缩态;调节光腔中场模结构参量,能够得到连续的量子信息熵压缩态。该研究结果在多光子过程低噪声量子信息处理中具有一定意义。 相似文献
19.
压缩真空场与原子非线性作用系统中场熵的压缩特性 总被引:2,自引:0,他引:2
利用量子信息熵理论,研究了附加克尔介质的压缩真空场与二能级原子依赖强度耦合相互作用系统中场熵的压缩特性.讨论了初始压缩真空场的压缩度以及克尔非线性作用的强度对场熵压缩特性的影响.结果表明,无克尔介质量,场熵压缩的演化具有严格的周期性.克尔介质的非线性作用的强弱可以改变场熵压缩的周期性.在初始压缩真空场的压缩度较大(r=5)时,无论克尔介质作用的强弱如何变化,场熵始终处于被压缩状态. 相似文献
20.
The quadrature squeezing properties of an atom laser originating from atomic Bose-Einstein condensate interacting with light field are studied. We find that the squeezing properties of the atom laser are dependent on the initial light field interacting with the atomic Bose-Einstein condensate. If the initial light field cannot be squeezed, such as number state or coherent state light field, the atom laser as well cannot be squeezed. However, if the initial light field interacting with the atomic Bose-Einstein condensate being in squeezed state, the atom laser can be squeezed periodically, and its squeezing depth is dependent on the intensity of interatoms interaction. 相似文献