共查询到20条相似文献,搜索用时 31 毫秒
1.
We propose a method to prepare multipartite entangled states such as cluster states and graph states based on the cavity input-output process and single photon measurement. Two quantum gates, a controlled phase gate and a fusion gate between two atoms trapped in respective cavities, are proposed to prepare atomic cluster states and graph states with one and two dimensions. We also introduce a scheme that can generate an arbitrary multipartite photon duster state which uses two coherent states as a qubit basis. 相似文献
2.
W. Wen Y. -K. Bai H. Fan 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,64(2-3):557-563
We analyze the entanglement evolution of two cavity photons being affected by the dissipation of two individual reservoirs. Under an arbitrary local unitary operation on the initial state, it is shown that there is only one parameter which changes the entanglement dynamics. For the bipartite subsystems, we show that the entanglement of the cavity photons is correlated with that of the reservoirs, although the local operation can delay the time at which the photon entanglement disappears and advance the time at which the reservoir entanglement appears. Furthermore, via a new defined four-qubit entanglement measure and two three-qubit entanglement measures, we study the multipartite entanglement evolution in the composite system, which allows us to analyze quantitatively both bipartite and multipartite entanglement within a unified framework. In addition, we also discuss the entanglement evolution with an arbitrary initial state. 相似文献
3.
Jian-Song Zhang Fen Liu Ai-Xi Chen 《International Journal of Theoretical Physics》2016,55(9):4016-4026
We investigate the effects of classical driving fields on the dynamics of purity, spin squeezing, and genuine multipartite entanglement (based on the Peres-Horodecki criterion ) of three two-level atoms within three separated cavities prepared in coherent states in the presence of decoherence. The three qubits are initially entangled and driven by classical fields. We obtain an analytical solution of the present system using the superoperator method. We find that the genuine multipartite entanglement measured by an entanglement monotone based on the Peres-Horodecki criterion can stay zero for a finite time and revive partially later. This phenomenon is similar to the sudden death of entanglement of two qubits and can be controlled efficiently by the classical driving fields. The amount of purity, spin squeezing, and genuine multipartite entanglement decrease with the increase of mean photon number of cavity fields. Particularly, the purity and genuine multipartite entanglement could be simultaneously improved by the classical driving fields. In addition, there is steady state genuine multipartite entanglement which can also be adjusted by the classical driving fields. 相似文献
4.
We propose a method of generating multipartite entanglement by considering the interaction of a system of N two-level atoms in a cavity of high quality factor with a strong classical driving field. It is shown that, with a judicious choice of the cavity detuning and the applied coherent field detuning, vacuum Rabi coupling produces a large number of important multipartite entangled states. It is even possible to produce entangled states involving different cavity modes. Tuning of parameters also permits us to switch from Jaynes-Cummings to anti-Jaynes-Cummings-like interaction. 相似文献
5.
远程制备多粒子纯态 总被引:2,自引:1,他引:1
我们提出了一个远程制备三种形式的多粒子纯态的方案,远程制备一般形式的多粒子纯态及两种特殊情况下的多粒子纯态.首先利用大失谐腔制备出N个原子的纠缠态[14],并将这N个原子分配给Alice和Bob等其他的参与者.然后Alice根据要远程制备的态对她的原子进行相应的单原子投影测量,并且将测量结果以经典信息的方式告诉给其他参与者.其他参与者根据收到的信息决定对自己的原子要么不操作,要么进行特定的操作,来转换他们所共享的纠缠态,最终除Alice以外的参与者就会处于期望的纠缠态.每一种情况下的信息消耗都是很少的,只消耗一量子比特和一经典比特.整个方案都基于现有的腔量子电动力学技术,因此该方案是可行性的. 相似文献
6.
Entanglement evolution of three-qubit mixed states in multipartite cavity—reservoir systems 下载免费PDF全文
We analyze the multipartite entanglement evolution of three-qubit mixed states composed of a GHZ state and a W state.For a composite system consisting of three cavities interacting with independent reservoirs,it is shown that the entanglement evolution is restricted by a set of monogamy relations.Furthermore,as quantified by the negativity,the entanglement dynamical property of the mixed entangled state of cavity photons is investigated.It is found that the three cavity photons can exhibit the phenomenon of entanglement sudden death(ESD).However,compared with the evolution of a generalized three-qubit GHZ state which has the equal initial entanglement,the ESD time of mixed states is later than that of the pure state.Finally,we discuss the entanglement distribution in the multipartite system,and point out the intrinsic relation between the ESD of cavity photons and the entanglement sudden birth of reservoirs. 相似文献
7.
Recently Yang, Chu, and Han [Phys. Rev. A 70 (2004) 022329]
presented a new type of multipartite entangled states for implementing efficient many-party controlled teleportation of multiqubit quantum
information. Here we propose a simple scheme for preparing such a type
of multi-atom entangled states in cavity quantum electrodynamics (QED).
The scheme involves atom-cavity interaction with large detuning,
and is immune to the cavity decay and the thermal field states. Some practical analyses show its availability with the present technology. 相似文献
8.
Quantum controlled phase gate and cluster states
generation via two superconducting quantum interference devices in a
cavity 总被引:3,自引:0,他引:3
Z.-Y. Xue G. Zhang P. Dong Y.-M. Yi Z.-L. Cao 《The European Physical Journal B - Condensed Matter and Complex Systems》2006,52(3):333-336
A scheme for implementing 2-qubit quantum controlled phase gate (QCPG) is proposed with two superconducting quantum interference
devices (SQUIDs) in a cavity. The gate operations are
realized within the two lower flux states of the SQUIDs by using a quantized cavity field and classical microwave pulses.
Our scheme is achieved without any type of measurement, does not use the cavity mode as the data bus and only requires a very
short resonant interaction of the SQUID-cavity system. As an application of the QCPG operation, we also propose a scheme for
generating the cluster
states of many SQUIDs. 相似文献
9.
We propose a scheme for implementing a measurement of GHZ entanglement for a multipartite system via cavity QED. In the scheme the atoms interact simultaneously with a highly detuned cavity mode with the assistant of a classical field. The scheme is insensitive to the cavity decay and the thermal field. A set of GHZ states can be exactly distinguished via detecting atomic state in a simple way. 相似文献
10.
Comparability of multipartite entanglement 总被引:1,自引:0,他引:1
We prove, in a multipartite setting, that it is always feasible to exactly transform a genuinely m-partite entangled pure state with sufficient many copies to any other m-partite state via local quantum operation and classical communication. This result affirms the comparability of multipartite entangled pure states. 相似文献
11.
An entangled multipartite system coupled to a zero-temperature bath undergoes rapid disentanglement in many realistic scenarios due to local, symmetry-breaking differences in the particle-bath couplings. We show that locally controlled perturbations, addressing each particle individually, can impose a symmetry allowing the existence of decoherence-free multipartite entangled systems. 相似文献
12.
Multipartite entanglement in the interaction system between a single-mode microwave cavity field and superconducting charge qubits 下载免费PDF全文
This paper proposes a method of generating multipartite entanglement through using
d.c. superconducting quantum interference devices (SQUID) inside a standing
wave cavity. In this scheme, the d.c. SQUID works in the charge region. It
is shown that, a large number of important multipartite entangled states can
be generated by a controllable interaction between a cavity field and
qubits. It is even possible to produce entangled states involving different
cavity modes based on the measurement of charge qubits states. After such
superpositions states are created, the interaction can be switched off by
the classical magnetic field through the SQUID, and there is no information
transfer between the cavity field and the charge qubits. 相似文献
13.
14.
We explore the possibility of an N-qubit (N>3) Grover
search in cavity QED, based on a fast operation of an N-qubit
controlled phase-flip with atoms in resonance with the cavity mode.
We demonstrate both analytically and numerically that our scheme
can be achieved efficiently to find a marked state with high
fidelity and high success probability. As an example, a ten-qubit
Grover search is simulated specifically under the discussion of
experimental feasibility and challenge. We argue that our scheme is
applicable to the case involving an arbitrary number of qubits. As
cavity decay is involved in our quantum trajectory treatment, we
can analytically understand the implementation of a Grover search
subject to dissipation, which will be very helpful for relevant
experiments. 相似文献
15.
We derive a general relation between the nonanalyticities of the ground state energy and those of a subclass of the multipartite generalized global entanglement (GGE) measure defined by de Oliveira et al. [Phys. Rev. A 73, 010305(R) (2006)] for many-particle systems. We show that GGE signals both a critical point location and the order of a quantum phase transition (QPT). We also show that GGE allows us to study the relation between multipartite entanglement and QPTs, suggesting that multipartite but not bipartite entanglement is favored at the critical point. Finally, using GGE we were able, at a second-order QPT, to define a diverging entanglement length (EL) in terms of the usual correlation length. We exemplify this with the XY spin-1/2 chain and show that the EL is half the correlation length. 相似文献
16.
We propose a quantum teleportation scheme for tripartite entangled coherent state (ECS) with continuous variable. Our scheme is feasible and economical in the sense that we need only linear optical devices such as beam splitters, phase shifters and photon detectors and employ three bipartite maximally ECSs as quantum channels. We also generalize the tripartite scheme into multipartite ease and calculate the minimum average fidelity for the schemes in tripartite and multipartite cases. 相似文献
17.
Paternostro M Vitali D Gigan S Kim MS Brukner C Eisert J Aspelmeyer M 《Physical review letters》2007,99(25):250401
We propose an immediately realizable scheme showing signatures of multipartite entanglement generated by radiation pressure in a cavity system with a movable mirror. We show how the entanglement involving the inaccessible massive object is unraveled by means of field-field quantum correlations and persists within a wide range of working conditions. Our proposal provides an operative way to infer the quantum behavior of a system that is only partially accessible. 相似文献
18.
Controlled phase gates based on two nonidentical quantum dots trapped in separate cavities 下载免费PDF全文
We propose a scheme for realizing two-qubit controlled phase gates on two nonidentical quantum dots trapped in separate cavities. In our scheme, each dot simultaneously interacts with one highly detuned cavity mode and two strong driven classical fields. During the gate operation, the quantum dots undergo no transition, while the system can acquire different phases conditional on different states of the quantum dots. With the application of the single-qubit operations, two-qubit controlled phase gates can be realized. 相似文献
19.
Min-Zhe Piao Hong-Fu Wang Xiao-Qiang Shao Xin Ji Shou Zhang 《International Journal of Theoretical Physics》2011,50(10):3033-3042
We propose an efficient scheme for preparing multi-qubit graph states via spin networks. The classical types of graph states including cluster state, Greenberger-Horne-Zeilinger state and circle-shaped states can be generated by using imaginary SWAP gate. Our method makes the generation of multipartite entangled graph states more efficient than the ones based on conventional controlled-NOT and controlled phase flip gate for solid-state devices. 相似文献
20.
We show that nonlinear resonances in a classically mixed phase space allow us to define generic, strongly entangled multipartite quantum states. The robustness of their multipartite entanglement increases with the particle number, i.e., in the semiclassical limit, for those classes of diffusive noise which assist the quantum-classical transition. 相似文献