共查询到20条相似文献,搜索用时 15 毫秒
1.
From the knotted pictures this article gives a possible quantitative measure
of the degree of entanglement. We suggest to use the area ratio to measure
the degree of entanglement, moreover, from the two parts of the
non-overlapping area we can also know vividly and pictorially the phase
difference between the two variable coefficients
α and β. 相似文献
2.
This article discusses the separability of the pure states and mixed states of the quantum network of twonodes by means of the criterion of no entanglement in terms of the covariance correlation tensor in quantum networktheory, i.e. for a composite system consisting of two nodes. The covariance correlation tensor Mjk(1, 2) is equal to zerofor all possible j and k. 相似文献
3.
This article discusses the complete separability and partial separability of the pure states of the quantumnetwork of three nodes by means of the criterion of entanglement in terms of the covariance correlation tensor in quantumnetwork theory. 相似文献
4.
QIAN Shang-Wu GU Zhi-Yu 《理论物理通讯》2004,42(7)
By means of the criterion of entanglement in terms of the covariance correlation tensor in quantum network theory, this article discusses the general solution for the complete separability of the pure quantum state with real coefficients for a quantum network of any nodes. 相似文献
5.
GUZhi-Yu QIANShang-Wu 《理论物理通讯》2003,40(1):33-38
This article discusses the complete separability and partial separability of the pure states of the quantum network of three nodes by means of the criterion of entanglement in terms of the covariance correlation tensor in quantum network theory. 相似文献
6.
QIANShang-Wu GUZhi-Yu 《理论物理通讯》2004,42(1):69-73
By means of the criterion of entanglement in terms of the covariance correlation tensor in quantum network theory, this article discusses the generalsolution for the complete separability of the pure quantum state with real coefficients for a quantum network of any nodes. 相似文献
7.
This article discusses the separability of the pure and mixed states of the quantum network of four nodesby means of the criterion of entanglement in terms of the covariance correlation tensor in quantum network theory. 相似文献
8.
GU Zhi-Yu QIAN Shang-Wu 《理论物理通讯》2008,49(5):1163-1164
This paper gives the knotted picture of the unknown quantum state in the process of quantum teleportation and the surgical knotted operations of the unitary operators operated on the teleported quantum state. 相似文献
9.
This article discusses the complete separability and partial separability of the mixed states of quantumnetwork of three nodes by means of the criterion of entanglement in terms of the covariance correlation tensor in quantumnetwork theory. 相似文献
10.
QIAN Shang-Wu GU Zhi-Yu 《理论物理通讯》2004,42(9)
By using the block division method in matrix calculus, this article successfully calculate the expectationvalues of the generating operators and the correlation tensors for quantum network of any nodes. Thence, by meansof the criterion of entanglement in terms of the covariance correlation tensor in quantum network theory, this articlediscusses the complete and partial separability conditions of the mixed quantum state for a quantum network of anynodes and judge the separability of a quantum state in the generalcase of any nodes for two examples. 相似文献
11.
GUZhi-Yu QIANShang-Wu 《理论物理通讯》2003,40(2):151-156
This article discusses the complete separability and partial separability of the mixed states of quantum network of three nodes by means of the crJterlon of entanglement in terms of the covarJance correlation tensor in quantum network theory. 相似文献
12.
QIANShang-Wu GUZhi-Yu 《理论物理通讯》2004,42(3):351-360
By using the block division method in matrix calculus, this article successfully calculate the expectation values of the generating operators and the correlation tensors for quantum network of any nodes. Thence, by means of the criterion of entanglement in terms of the covariance correlation tensor in quantum network theory, this article discusses the complete and partial separability conditions of the mixed quantum state for a quantum network of any nodes and judge the separability of a quantum state in the general case of any nodes for two examples. 相似文献
13.
A deterministic quantum key distribution scheme using two non-orthogonal entangled states is proposed.In the proposed scheme,communicators share key information by exchanging one travelling photon with two random and secret polarization angles.The security of the distributed key is guaranteed by three checking phases in three-way channel and the communicators' secret polarization angles. 相似文献
14.
We investigate the state or entanglement transfer through a two-dimensional spin network. We show that for state transfer, better fidelity can be gained along the diagonal direction but for entanglement transfer, when the initial entanglement is created along the boundary, the concurrence is more inclined to propagate along the boundary. This behavior is produced by quantum mechanical interference and the communication quality depends on the precise size of the network. For some number of sites, the fidelity in a two-dimensional channel is higher than one-dimensional case. This is an important result for realizing quantum communication through high dimension spin chain networks. 相似文献
15.
We investigate the state or entanglement transfer through a two-dimensional spin network. We show that for state transfer, better fidelity can be gained along the diagonal direction but for entanglement transfer, when the initial entanglement is created along the boundary, the concurrence is more inclined to propagate along the boundary. This behavior is produced by quantum mechanical interference and the communication quality depends on the precise size of the network. For some number of sites, the fidelity in a two-dimensional channel is higher than one-dimensional case. This is an important result for realizing quantum communication through high dimension spin chain networks. 相似文献
16.
GU Zhi-Yu QIAN Shang-Wu 《理论物理通讯》2009,51(5):769-772
This paper briefly introduces the five types of the surgical operations in knot theory and obtains the expression of single qubit quantum logic gate in terms of these surgical operations. 相似文献
17.
18.
Quantum entanglement dynamics of two Tavis-Cummings atoms interacting with the quantum light sources in a cavity is investigated. The results show the phenomenon that the concurrence disappears abruptly in a finite time, which depends on the initial atomic states and the properties of squeezed states. We find that there are two decoherence-free states in squeezed vacuum fields: one is the singlet state, and the other entangled state is the state
that combines both excited states and ground states with a relative phase being equal to the phase of the squeezed state. 相似文献
19.
20.
LIU Jin XIANG Shao-Hua CUI Hui-Ping LI Jian 《理论物理通讯》2009,51(4):637-640
We study the time evolution of two two-state systems (two qubits) initially in the pure entangled states or the maximally entangled mixed states interacting with the individual environmental noise. It is shown that due to environment noise, all quantum entangled states are very fragile and become a classical mixed state in a short-time limit. But the environment can affect entanglement in very different ways. The type of decoherence process for certain entangled states belongs to amplitude damping, while the others belong to dephasing decoherenee. 相似文献