共查询到20条相似文献,搜索用时 62 毫秒
1.
We analyze the classical and quantum correlation properties of the standard and so-called quasiclassical depolarizing channel with correlated noise and non-Markovian dephasing channel, specifically we use the quantum discord, entanglement, and measurement-induced disturbance (MID) to measure the quantum correlations. For the depolarizing channel, we find that the memory effect has more influence on the MID and quantum discord than entanglement. For the dephasing channel, we show that the non-Markovian dephasing channel is more robust than Markovian dephasing channel against deeoherence. We also find that at first MID and quantum discord take different values, and then after a specific time they will take almost the same value and both decay monotonically in the same way. 相似文献
2.
研究了两种典型的量子纠缠消相干现象对确定型量子态远程制备方案的影响.首先对该确定型远程制备方案进行了分析,得到该方案确定性和比特消耗情况; 然后通过分析制备过程中纠缠消相干现象对系统的影响得出: 在极化消相干过程中,该系统保真度与目标量子比特在Bloch球上的经度选择无关,仅与目标比特的纬度和消相干的大小有关;在相位消相干中,该系统的保真度不会受到消相干的影响,仅与目标量子态的纬度相关.
关键词:
远程制备
纠缠消相干
通信消耗
保真度 相似文献
3.
Jing Ma Li-Nan Jiang Si-Yuan Yu Qi-Wen Ran Li-Ying Tan 《International Journal of Theoretical Physics》2014,53(11):3843-3855
We investigate the entanglement dynamics of the two-qubit entanglement quantum system when they transmitted through the Pauli channels and the depolarizing channel both independently or collectively. Making use of the concurrence we found that the entanglement of a kind of mixed two-qubit system defined in this paper can be preserved in the collective Pauli σ y noise channel, but the entanglement of the other kind of mixed two-qubit system can be preserved in the collective Pauli σ z noise channel. Meanwhile, our quantum systems will undergoing the entanglement sudden death (ESD) in collective depolarizing channel when they return to the maximally entangled Bell states. The reason is the Landblad operators in depolarizing channel are non-commuting operators and this finding is in accord with the previous study. 相似文献
4.
Li-Guo Qin Li-Jun Tian Guo-Hong Yang 《International Journal of Theoretical Physics》2013,52(12):4313-4322
We study the thermal entanglement and teleportation using quantum dot as the quantum channel. We firstly investigate the evolution of entanglement in the vertical quantum dot, then focus on the effects of the important parameters of the system on the teleported fidelity under different conditions. We obtain the critical temperature of suddenly dead entanglement. Based on Bell measurements in two subspaces, the isotropy and anisotropy subspaces, we can find that the anisotropy measurements always overmatch the isotropy ones. Moreover, we obtain the high-fidelity teleportation for quantum dot as quantum channel when the parameters are adjusted. The possible applications of quantum dot are expected in quantum teleportation 相似文献
5.
Protection of entanglement from disturbance of the environment is an essential task in quantum information processing. We investigate the effect of the weak measurement and reversal (WMR) on the protection of the entanglement for an arbitrarily entangled two-qubit pure state from these three typical quantum noisy channels, i.e., amplitude damping channel, phase damping channel and depolarizing quantum channel. Given the parameters of the Bell-like initial qubits’ state |ψ〉 = a|00〉 + d|11〉, it is found that the WMR operation indeed helps for protecting distributed entanglement from the above three noisy quantum channels. But for the Bell-like initial qubits’ state |?〉 = b|01〉 + c|10〉, the WMR operation only protects entanglement in the amplitude damping channel, not for the phase damping and depolarizing quantum channels. In addition, we discuss how the concurrence and the success probability behave with adjusting the weak or the reversal weak measurement strength. 相似文献
6.
Using convex-roof extended negativity, we generalize previous qubit results of entanglement distribution and entanglement dynamics into arbitrary-dimensional quantum systems for isotropic states and the depolarizing channel. We further investigate a relation between these two types of entanglement properties. 相似文献
7.
8.
Properties on the distant distribution of entanglement for arbitrary two-qubit pure states via noisy quantum channels 下载免费PDF全文
This paper investigates the change of entanglement for transmitting
an arbitrarily entangled two-qubit pure state via one of three
typical kinds of noisy quantum channels: amplitude damping
quantum channel, phase damping quantum channel and depolarizing
quantum channel. It finds, in all these three cases, that the output
distant entanglement (measured by concurrence) reduces
proportionately with respect to its initial amount, and the decaying
ratio is determined only by the noisy characteristics of quantum
channels and independent of the form of initial input state. 相似文献
9.
We study the behavior of cooperative multiplayer quantum games [Q. Chen, Y. Wang, J.T. Liu, and K.L. Wang, Phys. Lett. A 327 (2004) 98; A.P. Flitney and L.C.L. Hollenberg, Quantum Inf. Comput. 7 (2007) 111] in the presence of decoherence using different quantum channels such as amplitude damping, depolarizing and phase damping. It is seen that the outcomes of the games for the two damping channels with maximum values of decoherence reduce to same value. However, in comparison to phase damping channel, the payoffs of cooperators are strongly damped under the influence amplitude damping channel for the lower values of decoherence parameter. In the case of depolarizing channel, the game is a no-payoff game irrespective of the degree of entanglement in the initial state for the larger values of decoherence parameter. The decoherence gets the cooperators worse off. 相似文献
10.
Achieving dynamical speedup of evolution in an open quantum system plays a key role in many technological applications. However, how to detect quantum speedup is unclear. In this work, a method to witness quantum speedup through the measure of the mutual information is presented. It is shown that the speed of evolution of a quantum system, can be witnessed by calculating the mutual information variation, whose increase is a clear signature of dynamical speedup. The result is explained by considering the time evolution of two qubits under a one‐sided noisy channel, finding out that the mechanism for the quantum speedup is closely associated with the total exchange of information between the system and its environment, which can be expressed by the variation of mutual information. Quantitatively, the average speed of evolution is shown proportional to the average variation of the mutual information in an interval of time. The conclusion can not only explain why the quantum entanglement (or quantum coherence) and the classical correlation are neither necessary nor sufficient to speed up the quantum evolution, but also give a vital way of detecting quantum speedup in realistic environments. 相似文献
11.
Jiaqiang Zhao Meijiao Wang Lianzhen Cao Yang Yang Xia Liu Qinwei Zhang Huaixin Lu Kellie Ann Driscoll 《Entropy (Basel, Switzerland)》2021,23(11)
Knowing the level of entanglement robustness against quantum bit loss or decoherence mechanisms is an important issue for any application of quantum information. Fidelity of states can be used to judge whether there is entanglement in multi-particle systems. It is well known that quantum channel security in QKD can be estimated by measuring the robustness of Bell-type inequality against noise. We experimentally investigate a new Bell-type inequality (NBTI) in the three-photon Greenberger–Horne–Zeilinger (GHZ) states with different levels of spin-flip noise. The results show that the fidelity and the degree of violation of the NBTI decrease monotonically with the increase of noise intensity. They also provide a method to judge whether there is entanglement in three-particle mixed states. 相似文献
12.
Y. Zhou G.-F. Zhang 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,47(2):227-231
We study quantum teleportation via a two-qubit Heisenberg
XXZ chain under an inhomogeneous magnetic field. We first consider entanglement
teleportation, and then focus on the teleportation fidelity under different
conditions. The effects of anisotropy and the magnetic field, both uniform
and inhomogeneous, are discussed. We also find that, though entanglement
teleportation does require an entangled quantum channel, a nonzero critical
value of minimum entanglement is not always necessary. 相似文献
13.
Entanglement is the crucial resource for different quantum information processing tasks. While conventional studies focus on the entanglement of bipartite or multipartite quantum states, recent works have extended the scenario to the entanglement of quantum channels, an operational quantification of the channel entanglement manipulation capability. Based on the recently proposed channel entanglement resource framework, here we study a further task of resource detection—witnessing entanglement of quantum channels. We first introduce the general framework and show how channel entanglement detection is related to the Choi state of the channel, enabling channel entanglement detection via conventional state entanglement detection methods. We also consider entanglement of multipartite quantum channels and use the stabilizer formalism to construct entanglement witnesses for circuits consisting of controlled-Z gates. We study the effectiveness of the proposed detection methods and compare their performance for several typical channels. Our work paves the way for systematic theoretical studies of channel entanglement and practical benchmarking of noisy intermediate scaled quantum devices. 相似文献
14.
GONG Lun-Xun PAN Jun-Ting 《理论物理通讯》2007,48(5):787-790
The modified mapping method is further improved by the expanded expression of u(ξ) that contains the terms of the first-order derivative of function f(ξ). Some new exact solutions to the mBBM equation are determined by means of the method. We can obtain many new solutions in terms of the Jacobi elliptic functions of the equation. 相似文献
15.
We introduce an operational interpretation for pure-state global multipartite entanglement based on quantum estimation. We show that the estimation of the strength of low-noise locally depolarizing channels, as quantified by the regularized quantum Fisher information, is directly related to the Meyer-Wallach multipartite entanglement measure. Using channels that depolarize across different partitions, we obtain related multipartite entanglement measures. We show that this measure is the sum of expectation values of local observables on two copies of the state. 相似文献
16.
S. -H. Xiang K. -H. Song W. Wen Z. -G. Shi 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2011,62(2):289-296
We study entanglement properties of two-mode
squeezed thermal states subjected to two sources of decoherence: the
common reservoirs and the bosonic memory Gaussian channel. For the
former one, we find that there exist three different behaviors:
no-sudden death, sudden death, and no-creation of entanglement. The
range of parameters characterizing these processes is obtained. For
the latter one, we obtain a threshold in the degree of squeezing
above which the input states remain always entangled. Otherwise, no
entanglement is allowed in bosonic Gaussian channel with memory
effect. We show that a degree of memory for quantum channel can be
help to increase the initial entanglement, while the mean number of
added thermal photons is to fasten the decoherence
process. 相似文献
17.
We investigate the transient spontaneous quantum synchronization between two qubits interacting with a common non-Markovian environment based on a collision model. We are mainly interested in the effect of non-Markovianity on the synchronization between two qubits. We find that the non-Markovianity always delay the anti-synchronization and decrease the parameter region where the qubits get anti-synchronized. Meanwhile, we define V to characterize the visibility of synchronization and show that there is an apparent link among V, entanglement and quantum mutual information whether in the Markovian or non-Markovian regimes when the environment is in the vacuum state. Moreover, with the increase of temperature, the parameter region of the emergence of anti-synchronization and the time to get anti-synchronized in the non-Markovian regime gradually approaches that in the Markovian regime. The high temperature decreases the parameter region of the emergence of anti-synchronization in both Markovian and non-Markovian regimes, and breaks the connection among V, entanglement and quantum mutual information. 相似文献
18.
Michał Horodecki Jonathan Oppenheim Andreas Winter 《Communications in Mathematical Physics》2007,269(1):107-136
We consider a quantum state shared between many distant locations, and define a quantum information processing primitive, state merging, that optimally merges the state into one location. As announced in [Horodecki, Oppenheim, Winter, Nature 436, 673 (2005)], the optimal entanglement cost of this task is the conditional entropy if classical communication is free. Since this quantity can be negative, and the state merging rate measures partial quantum information, we find that quantum information can be negative. The classical communication rate also has a minimum rate: a certain quantum mutual information. State merging enabled one to solve a number of open problems: distributed quantum data compression, quantum coding with side information at the decoder and sender, multi-party entanglement of assistance, and the capacity of the quantum multiple access channel. It also provides an operational proof of strong subadditivity. Here, we give precise definitions and prove these results rigorously. 相似文献
19.
Transfer of entanglement and information is studied for quantum teleportation of an unknown entangled state through noisy quantum channels. We find that the quantum entanglement of the unknown state can be lost during the teleportation even when the channel is quantum correlated. We introduce a fundamental parameter of correlation information which dissipates linearly during the teleportation through the noisy channel. Analyzing the transfer of correlation information, we show that the purity of the initial state is important in determining the entanglement of the replica state. 相似文献
20.
Margarita A. Man’ko 《Journal of Russian Laser Research》2017,38(3):211-222
We discuss the notions of mutual information and conditional information for noncomposite systems, classical and quantum; both the mutual information and the conditional information are associated with the presence of hidden correlations in the state of a single qudit. We consider analogs of the entanglement phenomena in the systems without subsystems related to strong hidden quantum correlations. 相似文献