共查询到20条相似文献,搜索用时 410 毫秒
1.
This paper proposes a feasible scheme for the quantum teleportation
of tripartite entangled coherent states by using linear optical
devices such as beam splitters, phase shifters and photo detectors.
The scheme is based on the bipartite maximally entangled coherent
state and the tripartite entangled coherent state with bipartite
maximal entanglement as quantum channels. It shows that when the
mean number of photons is equal to 2, the total minimum of the average
fidelity for an arbitrary tripartite entangled state is 1-0.67×10 -3. 相似文献
2.
This paper proposes an efficient scheme for deterministic generation
of entangled coherent states for two atomic samples. In the scheme
two collections of atoms are trapped in an optical cavity and driven
by a classical field. Under certain conditions the two atomic
samples evolve from an coherent state to an entangled coherent
state. During the interaction the cavity mode is always in the
vacuum state and the atoms have no probability of being populated in
the excited state. Thus, the scheme is insensitive to both the
cavity decay and atomic spontaneous emission. 相似文献
3.
4.
Generation of entangled coherent states for two cavity modes via resonant interaction with a V-type three-level atom 下载免费PDF全文
This paper proposes a scheme for the generation of entangled coherent states for two cavity modes. In the scheme a V-type three-level atom is sent through a two-mode cavity filled with a coherent field. After the atom cavity interaction and detection of the atomic state the cavity modes may evolve to a superposition of two-mode coherent states. As the scheme is based on resonant atom-cavity interaction, the required interaction time is short, which is important in view of the decoherence. Moreover, additional classical pulses are unnecessary before and after the atom-cavlty interaction. 相似文献
5.
A scheme is proposed for the teleportation of an unknown atomic state. The scheme is based on the resonant interaction of atoms with a coherent cavity field. The mean photon-number of the cavity field is much smaller than one and thus the cavity decay can be effectively suppressed. Another advantage of the scheme is that only one cavity is required. 相似文献
6.
本文讨论了在双Λ型原子系统中制备相干叠加态的方法:一个Λ型系统通过控制激光而另一个Λ型系统采用部分受激拉曼绝热通道的方法.在理论上分析了产生任意相干叠加态的可能性并且讨论了透热系统在产生相干叠加态过程中的重要性.研究表明,没有透热过程是不可能制备出任意的叠加态.应用数值方法验证理论分析是正确,并且指出任意叠加态的产生只与控制脉冲的时间延迟有关. 相似文献
7.
We propose a simple scheme to generate an arbitrary photon-added coherent state of a travelling optical field by combining an array of degenerate parametric amplifiers and corresponding single-photon detectors. Particularly, when the single-photon-added coherent state is observed by developing the novel technique of Zavatta et al (2004 Science 306 660), we can simultar/eously obtain the generalized N-qubit W state. 相似文献
8.
9.
M.K. Tavassoly 《Optics Communications》2010,283(24):5081-5091
In this paper, using an exponential function of intensity of radiation field, two new classes of nonlinear coherent states will be constructed. For the first class, we choose the nonlinearity function as fβ(n) = exp(βn), where β characterizes the strength of the nonlinearity of the quantum system. We show that, the corresponding β-states possess a collection of non-classicality features, only for the particular values of β and z. But, interestingly there exists finite (threshold) values of β, for which all of the non-classicality signs will disappear, in appropriate regions around the origin of the complex plane (z < |Z|). It is then illustrated that, using this threshold (or greater) value of β, the corresponding β-states behave very similar to canonical coherent states, as the most classical quantum states, in approximately whole of the space. In the continuation, we motivate to find another class of nonlinear coherent states, limited to a unit disk centered at the origin, looking like the canonical coherent states in behavior, in exactly the whole range of |z| < 1. This purpose also will be achieved by considering the nonlinearity function as , where λ is a tunable nonlinearity parameter. The canonical coherent state's aspects of the corresponding λ-states will be refreshed, in particular cases, working with a threshold (or greater) value of λ. 相似文献
10.
This paper presents a method for generating entanglement molecules,
which is introduced by Dur (2001 Phys. Rev. A). In this
scheme, N ladder-type three-level atoms are sent through a
resonant weak coherent cavity field, then the system states are
measured. And the system field may collapse onto some possible types
of entanglement molecules. Meanwhile it discusses about the
interaction time from the experimental point of view, and compare
the result with the previous scheme proposed by Huang (2004 J.
Phys. B: At. Mol. Opt. Phys.). 相似文献
11.
Utilizing a current-biased Josephson junction (CBJJ) as a tunable coupler for superconducting transmission line resonators (TLRs), we propose a potentially practical scheme to create entangled coherent states of the two TLR modes. Then, the influence of TLRs decay on the prepared entangled states is analyzed. And an interesting phenomenon that even entangled coherent states are robustness against decay with small α is found. At last, the experimental feasibility and the challenge of our schemes have been discussed. 相似文献
12.
We propose a nearly perfect optical scheme for the quantum teleportation of
entangled coherent states using optical devices such as nonlinear Kerr media, beam
splitters, phase shifters, and photon detectors. Different from those previous
schemes, our scheme needs only ``yes' or `no' measurements of the photon number of
the related modes, i.e. nonzero- and zero-photon measurements, while in previous
schemes one has to exactly identify the even or odd parity character of the photon
numbers detected by detectors. 相似文献
13.
Balanced homodyne detection has been introduced as a reliable technique of reconstructing the quantum state of a single photon Fock state, which is based on coupling the single photon state and a strong coherent local oscillator in a beam splitter and detecting the field quadrature at the output ports separately. The main challenge associated with a tomographic characterization of the single photon state is mode matching between the single photon state and the local oscillator. Utilizing the heralded single photon generated by the spontaneous parametric process, the multi-mode theoretical model of quantum interference between the single photon state and the coherent state in the fiber beam splitter is established.Moreover, the analytical expressions of the temporal-mode matching coefficient and interference visibility and relationship between the two parameters are shown. In the experimental scheme, the interference visibility under various temporalmode matching coefficients is demonstrated, which is almost accordant with the theoretical value. Our work explores the principle of temporal-mode matching between the single photon state and the coherent photon state, originated from a local oscillator, and could provide guidance for designing the high-performance balanced homodyne detection system. 相似文献
14.
15.
ZOU Anhua 《Chinese Journal of Lasers》1994,3(2):117-127
ThenonclassicalpropertiesofthesuperpositioninvolvingtwosqueezingcoherentstatesZOUAnhua(DepartmentofPhysics,ShengraoTeacbors'C... 相似文献
16.
This paper proposes a scheme for generation of superpositions of
coherent states of the effective bosonic mode in a collection of
atoms. In the scheme an atomic sample interacts with a slightly
detuned cavity mode and a resonant strong classical field. Under
certain conditions the atomic system evolves from a coherent state
to a superposition of coherent states. 相似文献
17.
A scheme is proposed to generate arbitrary, discrete
superpostions of squeezed coherent states of the squeezed center of mass of
$N$ trapped ions along a straight line in phase space.
The scheme is based on a
resonant bichromatic excitation of each trapped ion that generates
displacement and squeezing in the vibrational motion conditioned to each
internal state. In this paper, we also show that such a method can be
used for the engineering of motional quantum states. 相似文献
18.
《Physics letters. A》2020,384(26):126656
In this paper, we introduce an algebraic approach to construct Fokas-Lagerstrom coherent states. To do so, we define deformed creation and annihilation operators associated to this system and investigate their algebra. We show that these operators satisfy the f-deformed Weyl-Heisenberg algebra. Then, we propose a theoretical scheme to generate the aforementioned coherent states. The present contribution shows that the Fokas-Lagerstrom nonlinear coherent states possess some non-classical features. 相似文献
19.
In this paper the superpositions of two arbitrary coherent states |ψ〉 = α |β| + be^iψ |mβe^iδ〉 are constructed by using the superposition principle of quantum mechanics. The entropic squeezing effects of the quantum states are studied. The numerical results indicate that the amplitudes, the ratio between the amplitudes of two coherent states, the phase difference between the two components and the relative phase of the two coefficients play important roles in the squeezing effects of the position entropy and momentum entropy. 相似文献
20.
ZHENGShi-Biao 《理论物理通讯》2002,37(1):87-90
A method is presented for generating highly squeezed states of a cavity field via the atom-cavity field interaction of the Raman type.In the scheme a sequence of three-level Λ-type atoms interacts with a cavity field,displaced by a classical source,in a Raman manner.Then the atomic states are measured.By this way the cavity field may collapse onto a superposition of several coherent states,which exhibits strong squeezing.The scheme can also be used to prepare superpositions of many two-mode coherent states for two cavity fields.The coherent states in each mode are on a straight line.This is the first way for preparing multi-component entangled coherent states of this type in cavity QED. 相似文献