共查询到20条相似文献,搜索用时 78 毫秒
1.
By using negativity as entanglement measure, we have investigated the effect of local decoherence from a non-Markovian environmenton the time evolution of entanglement of three-qubit states including the GHZ state, the W state, and the Werner state. From the results, we find that the entanglement dynamics depends not only on the coupling strengths but also on the specific states of concern. Specifically, the entanglement takes different behaviors under weak or strong coupling and it varies with the quantum states under study. The entanglement of the GHZ state and the Werner state can be destroyed completely by the local decoherence, while the entanglement of the W state can survive through the local decoherence partially. 相似文献
2.
QIU Liang WANG An-Min MA Xiao-San 《理论物理通讯》2008,49(2):516-520
We analyze the time evolution of entanglement of two-qutrit system
within the framework of Milburn's model of intrinsic decoherence.
The entanglement evolution relies not only on the parameters of
system, but also on the concrete states either pure or mixed. The
linear entropy used to measure the extent to which the
intrinsic decoherence affects quantum states is evaluated. 相似文献
3.
Entanglement dynamics of a two-qutrit Heisenberg spin chain with the external magnetic fields and DM interaction under the intrinsic decoherence is investigated. Depending on whether there is inhomogeneous magnetic field, the entanglement amplification, i.e. the phenomenon that the finally stable entanglement is bigger than that of the initial one, is found for one kind of initial states. The reasons for the controllable entanglement amplification are discussed. 相似文献
4.
Finding the most robust entangled states during the whole process of decoherence is a particularly fundamental problem for quantum physics and quantum information processing. In this paper, the decoherence process of two-qubit system under two individual identical decoherence channels is investigated systematically. We find that although the robustness of two-qubit states with same initial entanglement is usually different, the Bell-like states are always the most robust entangled states during decoherence. That is to say, affected by the same amount of noise, the remain entanglement of an arbitrary two-qubit state is not more than that of a Bell-like state with the same initial entanglement. 相似文献
5.
Protection of entanglement from disturbance of the environment is an essential task marion processing. We examine the validity and limitation of the weak measurement and reversal in quantum infor- (WMR) operation in the protection of distributed entanglement from various decoherence sources. Since the entanglement variation can be investigated analytically for an arbitrarily entangled bipartite pure state under three kinds of typical noisy quantum channels, we show explicitly that the WMR operation indeed helps for protecting distributed entanglement from ampli- tude damping and phase damping, but not for depolarizing. Bxperimental feasibility for testing our results is discussed using current laboratory techniques. 相似文献
6.
SHAN Chuan-Jia CHENG Wei-Wen LIU Tang-Kun GUO De-Jun XIA Yun-Jie 《理论物理通讯》2008,49(6):1505-1514
Considering the dipole-dipole coupling intensity between two atoms and the field in the Fock state, the entanglement dynamics between two atoms that are initially entangled in the system of two two-level atoms coupled to a single mode cavity in the presence of phase decoherence has been investigated. The two-atom entanglement appears with periodicity without considering phase decoherence, however, the phase decoherence causes the decay of entanglement between two atoms, with the increasing of the phase decoherence coefficient, the entanglement will quickly become a constant value, which is affected by the two-atom initial state. Meanwhile the two-atom quantum state will forever stay in the maximal entangled state when the initial state is proper even in the presence of phase decoherence. On the other hand, the Bell violation and the entanglement do not satisfy the monotonous relation, a large Bell violation implies the presence of a large amount of entanglement under certain conditions, while a large Bell violation corresponds to a little amount of entanglement in certain situations. However, the violation of Bell-CHSH inequality can reach the maximal value if two atoms are in the maximal entangled state, or vice versa. 相似文献
7.
SHAO Bin ZENG Tian-Hai ZOU Jian 《理论物理通讯》2005,44(2):255-258
Taking the intrinsic decoherence effect into account, we investigate the time evolution of entanglement for two-qubit XYZ Heisenberg model in an external uniform magnetic field. Concurrence, the measurement of entanglement,is calculated. We show how the intrinsic decoherence modifies the time evolution of the entanglement and find that at short-time case, concurrence is oscillating as increasing magnetic field, which implies that entanglement may be enhanced or weakened in some time regions. 相似文献
8.
XIE Guo-Qiu WANG An-Min MA Xiao-San 《理论物理通讯》2006,46(7)
The entanglement evolution of multipartite quantum states under a spin environment is analyzed. Due to interaction, the extent to which the entanglement vanishes depends not only on the size of system and the structure of quantum states, but also on the exchange couplings with environment. The decoherence-free subspaces have been identified by using the linear entropy. 相似文献
9.
SHAO Bin ZENG Tian-Hai ZOU Jian 《理论物理通讯》2005,44(8)
Taking the intrinsic decoherence effect into account, we investigate the time evolution of entanglement for two-qubit XYZ Heisenberg model in an external uniform magnetic field. Concurrence, the measurement of entanglement,is calculated. We show how the intrinsic decoherence modifies the time evolution of the entanglement and find that at short-time case, concurrence is oscillating as increasing magnetic field, which implies that entanglement may be enhanced or weakened in some time regions. 相似文献
10.
XIE Guo-Qiu WANG An-Min MA Xiao-San 《理论物理通讯》2006,46(1):73-76
The entanglement evolution of multipartite quantum states under a spin environment is analyzed. Due to interaction, the extent to which the entanglement vanishes depends not only on the size of system and the structure of quantum states, but also on the exchange couplings with environment. The decoherence-free subspaces have been identified by using the linear entropy. 相似文献
11.
Three-Qubit Entanglement Sudden Death 总被引:1,自引:0,他引:1
GE Min ZHU Lin-Fan QIU Liang 《理论物理通讯》2008,49(6):1443-1448
We study entanglement dynamics of three-qubit system via negativity. Three atoms A, B, and C interact isolatedly with their own Jaynes-Cummings cavities a, b, and c. Aa system is prepared entangled with Bb and Cc, however, their mutual isolations forbid Aa interacting with system Bb and Cc. It is the same for system Bb and Cc. We show entanglement evolution of different three-qubit systems ABC, abc, Abc, and aBC and find entanglement sudden death effect. 相似文献
12.
Wei Song Da-Chuang Li Zhuo-Liang Cao 《International Journal of Theoretical Physics》2011,50(3):833-837
Using the factorization Law for entanglement decay derived by Konrad, T., et al.: Nature Phys. 4, 99 (2008), we investigate
the one-side and two-side local decoherence effect on the dynamics of the two-qubit entangled states. Under the depolarizing
channel and GAD channel with the nonzero temperature, we have found that any two-qubit states will experience ESD. Furthermore,
we also investigate the entanglement dynamics under the non-Markovian case. 相似文献
13.
We study the effect of decoherence on quantum Monty Hall problem under theinfluence of amplitude damping, depolarizing, and dephasing channels. It isshown that under the effect of decoherence, there is a Nash equilibrium ofthe game in case of depolarizing channel for Alice's quantum strategy.Whereas in case of dephasing noise, the game is not influenced by thequantum channel. For amplitude damping channel, Bob's payoffs are foundsymmetrical about a decoherence of 50% and the maximum occurs at this value of decoherence for his classical strategy. However, it is worth-mentioning that in case of depolarizing channel, Bob's classical strategy remains always dominant against any choice of Alice's strategy. 相似文献
14.
In this paper,we have investigated the quantum entanglement of quantum states undergoing decoherence from a spin environment which drives a quantum phase transition.From our analysis,we find that the entanglement dynamics depends not only on the coupling strength but also on the external magnetic field and the number of the freedom degrees of the environment.Specially,our results imply that the decay of the entanglement can be enhanced by the quantum phase transition of the environment when the system is coupled to the environment weakly.Additionally,the discussion of the case of the multipartite states with high dimensions is made. 相似文献
15.
In this paper, we have investigated the quantum entanglement of quantum states undergoing decoherence from a spin environment which drives a quantum phase transition. From our analysis, we find that the entanglement dynamics depends not only on the coupling strength but also on the external magnetic field and the number of the freedom degrees of the environment. Specially, our results imply that the decay of the entanglement can be enhanced by the quantum phase transition of the environment when the system is coupled to the environment weakly. Additionally, the discussion of the case of the multipartite states with high dimensions is made. 相似文献
16.
We study the effect of decoherence on quantum Monty Hall problem under the influence of amplitude damping, depolarizing, and dephasing channels. It is shown that under the effect of decoherence, there is a Nash equilibrium of the game in case of depolarizing channel for Alice's quantum strategy. Whereas in case of dephasing noise, the game is not influenced by the quantum channel. For amplitude damping channel, Bob's payoffs are found symmetrical about a decoherence of 50% and the maximum occurs at this value of decoherence for his classical strategy. However, it is worth-mentioning that in case of depolarizing channel, Bob's classical strategy remains always dominant against any choice of Alice's strategy. 相似文献
17.
The dynamic behavior of the entanglement for the pair cat states in the amplitude decoherence channel is studied by adopting the entanglement of formation determined by the concurrence. Then, we consider the teleportation by using joint measurements of the photon-number sum and phase difference with the pair cat states as an entangle resource and discuss the influence of amplitude decoherence on the mean fidelity of the teleportation. 相似文献
18.
The dynamic behavior of the entanglement for the pair cat states in the amplitude decoherence channel is studied by adopting the entanglement of formation determined by the concurrence. Then, we consider the teleportation by using joint measurements of the photon-number sum and phase difference with the pair cat states as an entangle resource and discuss the influence of amplitude decoherence on the mean fidelity of the teleportation. 相似文献
19.
Joanna K. Kalaga Wiesaw Leoski Radosaw Szczniak Jan Peina Jr. 《Entropy (Basel, Switzerland)》2022,24(3)
We consider a family of states describing three-qubit systems. We derived formulas showing the relations between linear entropy and measures of coherence such as degree of coherence, first- and second-order correlation functions. We show that qubit–qubit states are strongly entangled when linear entropy reaches some range of values. For such states, we derived the conditions determining boundary values of linear entropy parametrized by measures of coherence. 相似文献
20.
In this paper we describe how three qubit entanglement can be analyzed with local measurements. For this purpose we decompose entanglement witnesses into operators that can be measured locally. Our decompositions are optimized in the number of measurement settings needed for the measurement of one witness. Our method allows to detect true threepartite entanglement and especially GHZ-states with only four measurement settings. 相似文献