An experimentally feasible protocol for realizing dense coding by using a class of W-state in cavity quantum electrodynamics （QED） is proposed in this paper. The prominent advantage of our scheme is that the success...An experimentally feasible protocol for realizing dense coding by using a class of W-state in cavity quantum electrodynamics （QED） is proposed in this paper. The prominent advantage of our scheme is that the successful probability of the dense coding with a W-class state can reach 1. In addition, the scheme can be implemented by the present cavity QED techniques.展开更多
In the paper （Phys. Rev. 2006 A 4 062320） Agrawal et al. have introduced a kind of W-class state which can be used for the quantum teleportation of single-particle state via a three-particle von Neumann measurement,...In the paper （Phys. Rev. 2006 A 4 062320） Agrawal et al. have introduced a kind of W-class state which can be used for the quantum teleportation of single-particle state via a three-particle von Neumann measurement, and they thought that the state could not be used to teleport an unknown state by making two-particle and one-particle measurements. Here we reconsider the features of the W-class state and the quantum teleportation process via the W-class state. We show that, by introducing a unitary operation, the quantum teleportation can be achieved deterministically by making two-particle and one-particle measurements. In addition, our protocol is extended to the process of teleporting two-particle state and splitting information.展开更多
In this paper we present a remote state preparation scheme with a three-qubit W-class state in cavity QED. It has been shown that a special single-qubit state and a special two-qubit entangled state can be remotely pr...In this paper we present a remote state preparation scheme with a three-qubit W-class state in cavity QED. It has been shown that a special single-qubit state and a special two-qubit entangled state can be remotely prepared perfectly. Furthermore, the classical information cost in this scheme is less than that in the corresponding teleportation scheme and only a single-qubit projective measurement is made by the sender. We also generalize this idea to the multiqubit W-class state.展开更多
We present the entanglement measures of a tetrapartite W-class entangled system in a noninertial frame, where the transformation between Minkowski and Rindler coordinates is applied.Two cases are considered.First, whe...We present the entanglement measures of a tetrapartite W-class entangled system in a noninertial frame, where the transformation between Minkowski and Rindler coordinates is applied.Two cases are considered.First, when one qubit has uniform acceleration whilst the other three remain stationary.Second, when two qubits have nonuniform accelerations and the others stay inertial.The 1–1 tangle, 1–3 tangle, and whole entanglement measurements π4 and Π4, are studied and illustrated with graphics through their dependence on the acceleration parameter rd for the first case and rc and rd for the second case.It is found that the negativities(1–1 tangle and 1–3 tangle) and π-tangle decrease when the acceleration parameter rd or in the second case rc and rd increase, remaining a nonzero entanglement in the majority of the results.This means that the system will be always entangled except for special cases.It is shown that only the 1–1 tangle for the first case vanishes at infinite accelerations, but for the second case the 1–1 tangle disappears completely when r > 0.472473.An analytical expression for the von Neumann information entropy of the system is found and we note that it increases with the acceleration parameter.展开更多
W。D ü r 等。证明了经由本地操作和古典通讯(LOCC ) 从任意的 W 班状态的一个拷贝获得一个 GHZ 状态是不可能的[W。D ü r， G。Vidal，和 J.I Cirac， Phys。加快。一 62 (2000 ) 062314 ] 。在我们的纸，更一般的案例小心...W。D ü r 等。证明了经由本地操作和古典通讯(LOCC ) 从任意的 W 班状态的一个拷贝获得一个 GHZ 状态是不可能的[W。D ü r， G。Vidal，和 J.I Cirac， Phys。加快。一 62 (2000 ) 062314 ] 。在我们的纸，更一般的案例小心地被调查。我们首先证明与任意的 W 班状态的二个拷贝的供应，我们能总是构造一个明确的过程与非零可能性提取一个 GHZ 状态。然后基于这结果，为从任意的 W 班状态的 n 拷贝提取 GHZ 状态的一个简单过程被介绍。最后，我们简短讨论应用。展开更多
We propose an experimentally feasible teleportation scheme with three-atom W-class state,which was first proposed by Agrawal and Pati [P.Agrawal and A.Pati,Phys.Rev.A 74 (2006) 062320 ],in cavity QED.In this scheme at...We propose an experimentally feasible teleportation scheme with three-atom W-class state,which was first proposed by Agrawal and Pati [P.Agrawal and A.Pati,Phys.Rev.A 74 (2006) 062320 ],in cavity QED.In this scheme atoms interact simultaneously with a nonresonant cavity and there is no energy exchange between the atoms and the cavity.Thus it is insensitive to the cavity decay,which is of importance in view of experiment.展开更多
We give a protocol to prepare specially entangled W-class state of multi-atom which can be used to exactly teleport an arbitrarily unknown two-level two-atom state. During the process, the quantum in-formation is spli...We give a protocol to prepare specially entangled W-class state of multi-atom which can be used to exactly teleport an arbitrarily unknown two-level two-atom state. During the process, the quantum in-formation is split into n parts and the original quantum information can be sent to anyone of the n re-cipients with the other n-1 recipients' collaboration. In addition, we will give a suggestion to realize this scheme via QED cavity.展开更多
Entanglement plays an important role in quantum information science, especially in quantum communications. Here we present an efficient entanglement concentration protocol(ECP) for nonlocal atom systems in the partial...Entanglement plays an important role in quantum information science, especially in quantum communications. Here we present an efficient entanglement concentration protocol(ECP) for nonlocal atom systems in the partially entangled W-class states, using the single-photon input-output process regarding low-Q cavity and linear optical elements. Compared with previously published ECPs for the concentration of non-maximally entangled atomic states, our protocol is much simpler and more efficient as it employs the Faraday rotation in cavity quantum electrodynamics(QED) and the parameter-splitting method. The Faraday rotation requires the cavity with low-Q factor and weak coupling to the atom, which makes the requirement for entanglement concentration much less stringent than the previous methods, and achievable with current cavity QED techniques. The parameter-splitting method resorts to linear-optical elements only. This ECP has high efficiency and fidelity in realistic experiments, and some imperfections during the experiment can be avoided efficiently with currently available techniques.展开更多
We demonstrate that four sets of W-class states can be used to realize the deterministic quantum information splitting of an arbitrary three-atom state in cavity QED.The scheme does not involve Bell-state measurement ...We demonstrate that four sets of W-class states can be used to realize the deterministic quantum information splitting of an arbitrary three-atom state in cavity QED.The scheme does not involve Bell-state measurement and is insensitive to both the cavity decay and the thermal field.展开更多
We investigate the quantum characteristics of a three-particle W-class state and reveal the relationship between quan- tum discord and quantum entanglement under decoherence. We can also identify the state for which d...We investigate the quantum characteristics of a three-particle W-class state and reveal the relationship between quan- tum discord and quantum entanglement under decoherence. We can also identify the state for which discord takes a maximal value for a given decoherence factor, and present a strong bound on quantum entanglement-quantum discord. In contrast, a striking result will be obtained that the quantum discord is not always stronger than the entanglement of formation in the case of decoherence. Furthermore, we also theoretically study the variation trend of the monogamy of quantum correlations for the three-particle W-class state under the phase flip channel, and find that the three-particle W-class state could transform from polygamous into monogamous, owing to the decoherence.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 10674001)the Program of Education Department of Anhui University of China (Grant No KJ2007A002)the Youth Program of Fuyang Normal College of China (Grant No 2005LQ04)
文摘An experimentally feasible protocol for realizing dense coding by using a class of W-state in cavity quantum electrodynamics （QED） is proposed in this paper. The prominent advantage of our scheme is that the successful probability of the dense coding with a W-class state can reach 1. In addition, the scheme can be implemented by the present cavity QED techniques.
基金supported by the National Natural Science Foundation of China (Grant Nos. 10404007 and 60578055)the State Key Program for Basic Research of China (Grant No. 2007CB925204)
文摘In the paper （Phys. Rev. 2006 A 4 062320） Agrawal et al. have introduced a kind of W-class state which can be used for the quantum teleportation of single-particle state via a three-particle von Neumann measurement, and they thought that the state could not be used to teleport an unknown state by making two-particle and one-particle measurements. Here we reconsider the features of the W-class state and the quantum teleportation process via the W-class state. We show that, by introducing a unitary operation, the quantum teleportation can be achieved deterministically by making two-particle and one-particle measurements. In addition, our protocol is extended to the process of teleporting two-particle state and splitting information.
文摘In this paper we present a remote state preparation scheme with a three-qubit W-class state in cavity QED. It has been shown that a special single-qubit state and a special two-qubit entangled state can be remotely prepared perfectly. Furthermore, the classical information cost in this scheme is less than that in the corresponding teleportation scheme and only a single-qubit projective measurement is made by the sender. We also generalize this idea to the multiqubit W-class state.
基金Project partially supported by the CONACYT,Mexico under the Grant No.288856-CB-2016partially by 20190234-SIP-IPN,Mexicopartially by the program XXVIII Verano de la Investigación Científica 2018 supported by the Academia Mexicana de Ciencias
文摘We present the entanglement measures of a tetrapartite W-class entangled system in a noninertial frame, where the transformation between Minkowski and Rindler coordinates is applied.Two cases are considered.First, when one qubit has uniform acceleration whilst the other three remain stationary.Second, when two qubits have nonuniform accelerations and the others stay inertial.The 1–1 tangle, 1–3 tangle, and whole entanglement measurements π4 and Π4, are studied and illustrated with graphics through their dependence on the acceleration parameter rd for the first case and rc and rd for the second case.It is found that the negativities(1–1 tangle and 1–3 tangle) and π-tangle decrease when the acceleration parameter rd or in the second case rc and rd increase, remaining a nonzero entanglement in the majority of the results.This means that the system will be always entangled except for special cases.It is shown that only the 1–1 tangle for the first case vanishes at infinite accelerations, but for the second case the 1–1 tangle disappears completely when r > 0.472473.An analytical expression for the von Neumann information entropy of the system is found and we note that it increases with the acceleration parameter.
基金The project supported by National Natural Science Foundation of China under Grant No.10674025Funds from Key Laboratory of Quantum Information of University of Science and Technology of China
文摘根据 Agrawal 等的协议，我们为远距传物并且稠密的编码的实现建议一个洞证完计划。而不是使用 EPR 状态和 GHZ 状态，我们的计划对由把一个 W 班状态用作一条量隧道的一个粒子的损失更感觉迟钝。而且，我们的计划对热地有免疫力，并且不要求洞在整个过程留在真空状态。
基金National Natural Science Foundation of China under Grant No.10404039
文摘W。D ü r 等。证明了经由本地操作和古典通讯(LOCC ) 从任意的 W 班状态的一个拷贝获得一个 GHZ 状态是不可能的[W。D ü r， G。Vidal，和 J.I Cirac， Phys。加快。一 62 (2000 ) 062314 ] 。在我们的纸，更一般的案例小心地被调查。我们首先证明与任意的 W 班状态的二个拷贝的供应，我们能总是构造一个明确的过程与非零可能性提取一个 GHZ 状态。然后基于这结果，为从任意的 W 班状态的 n 拷贝提取 GHZ 状态的一个简单过程被介绍。最后，我们简短讨论应用。
文摘We propose an experimentally feasible teleportation scheme with three-atom W-class state,which was first proposed by Agrawal and Pati [P.Agrawal and A.Pati,Phys.Rev.A 74 (2006) 062320 ],in cavity QED.In this scheme atoms interact simultaneously with a nonresonant cavity and there is no energy exchange between the atoms and the cavity.Thus it is insensitive to the cavity decay,which is of importance in view of experiment.
基金Supported by the National Natural Science Foundation of China (Grant Nos. 60472017, 10575017)Educational Fund of Liaoning Province
文摘We give a protocol to prepare specially entangled W-class state of multi-atom which can be used to exactly teleport an arbitrarily unknown two-level two-atom state. During the process, the quantum in-formation is split into n parts and the original quantum information can be sent to anyone of the n re-cipients with the other n-1 recipients' collaboration. In addition, we will give a suggestion to realize this scheme via QED cavity.
基金supported by the National Natural Science Foundation of China(Grant Nos.61471050,61377097,11404031 and 61571060)the Fok Ying-Tong Education Foundation for Young Teachers in the Higher Education Institutions of China(Grant No.151063)+1 种基金the Fundamental Research Funds for the Central Universities(Grant No.2015RC28)the Fund of State Key Laboratory of Information Photonics and Optical Communications(Beijing University of Posts and Telecommunications)(Grant No.IPOC2015ZT05)
文摘Entanglement plays an important role in quantum information science, especially in quantum communications. Here we present an efficient entanglement concentration protocol(ECP) for nonlocal atom systems in the partially entangled W-class states, using the single-photon input-output process regarding low-Q cavity and linear optical elements. Compared with previously published ECPs for the concentration of non-maximally entangled atomic states, our protocol is much simpler and more efficient as it employs the Faraday rotation in cavity quantum electrodynamics(QED) and the parameter-splitting method. The Faraday rotation requires the cavity with low-Q factor and weak coupling to the atom, which makes the requirement for entanglement concentration much less stringent than the previous methods, and achievable with current cavity QED techniques. The parameter-splitting method resorts to linear-optical elements only. This ECP has high efficiency and fidelity in realistic experiments, and some imperfections during the experiment can be avoided efficiently with currently available techniques.
基金Supported by the National Natural Science Foundation of China under Grant No. 60807014the Natural Science Foundation of Jiangxi Province under Grant No. 2009GZW0005+1 种基金the Research Foundation of State Key Laboratory of Advanced Optical Communication Systemsand Networks,Shanghai Jiao Tong Universitythe Research Foundation of the Education Department of Jiangxi Province under GrantNo. GJJ09153
文摘We demonstrate that four sets of W-class states can be used to realize the deterministic quantum information splitting of an arbitrary three-atom state in cavity QED.The scheme does not involve Bell-state measurement and is insensitive to both the cavity decay and the thermal field.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11074002,61275119,and 11247256)the Doctoral Science Foundation of the Ministry of Education of China(Grant No.20103401110003)+2 种基金the Fund of the Education Department of Anhui Province for Outstanding Youth,China(Grant No.2012SQRL023)the Doctor Scientific Research Fund of Anhui University,China(Grant No.33190058)the Personal Development Foundation of Anhui Province,China(Grant No.2008Z018)
文摘We investigate the quantum characteristics of a three-particle W-class state and reveal the relationship between quan- tum discord and quantum entanglement under decoherence. We can also identify the state for which discord takes a maximal value for a given decoherence factor, and present a strong bound on quantum entanglement-quantum discord. In contrast, a striking result will be obtained that the quantum discord is not always stronger than the entanglement of formation in the case of decoherence. Furthermore, we also theoretically study the variation trend of the monogamy of quantum correlations for the three-particle W-class state under the phase flip channel, and find that the three-particle W-class state could transform from polygamous into monogamous, owing to the decoherence.
