arXiv subjects

Hai-Yang Song

Publications and source records attributed to Hai-Yang Song.

6 recordsLinked to original sources

arXiv2014

The relation between tangle and local unitary invariants for pure three and four-qubit states

A new form of local unitary (LU) transformation invariant is given for multi-qubit states . The general relation between tangle and the LU transformation invariant of pure three and four-qubit states is given. We find that the tangle actually is a special LU transformation invariant. Furthermore, the tangle is a important local unitary (LU) transformation invariant which is a nessesary condition for maximally multi-qubit entangled state.

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arXiv2014

Channel matrix, measurement matrix and collapsed matrix in teleportation

In this paper, two kinds of coefficient matrixes (channel matrix, measurement matrix)associated with the pure state for teleportation are presented, the general relation among channel matrix, measurement matrix and collapsed matrix is obtained. In addition, a criterion for teleportation that the number of coefficient of an unknown state is determined by the rank of the collapsed matrix is given.

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arXiv2011

A genuine maximally seven-qubit entangled state

Contrary to A.Borras et al.'s [1] conjecture, a genuine maximally seven-qubit entangled state is presented. We find a seven-qubit state whose marginal density matrices for subsystems of 1,2- qubits are all completely mixed and for subsystems of 3-qubits is almost completely mixed.

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arXiv2009

The relation of genuine multiqubit entanglement and controlled teleportation

Recently, Paolo Facchi et al. [Phys. Rev. A. 77, 060304 (R) (2008)] introduced the notion of maximally multipartite entangled states of n qubits. Here, we give a criterion for faithful controlled teleportation of an arbitrary two-qubit state via a five-qubit entangled state and obtain the general relation between the genuine five-qubit entangled state and controlled teleportation. This criterion can be extended to teleportation of an arbitrary N-qubit state using 2N+1-qubit entangled state. Furthermore, we study the optimal match of measuring basis and quantum channel.

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arXiv2007

Three-qubit pure-state canonical forms for Perfect Teleportation

Recently, Agrawal and Pati [Phys. Rev. A 74, 062320 (2006)] have given a class of W-states that can be used for perfect teleportation. Here, two canonical forms of perfect quantum channel are presented by transformation operator and the GHZ state and the W state are special case of those two canonical forms of perfect quantum channel. Furthermore, the orthogonal complete measurement bases are given.

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arXiv2007

Non-EPR pairs quantum channel for teleporting an arbitrary two-qubit state

Recently, Yeo and Chua [Phys. have given an explicit protocol for faithfully teleporting an arbitrary two-qubit state via a genuine four-qubit entangled state, which is not reducible to a pair of Bell states. Here, we present a transformation operator to give the criterion of for faithfully teleporting arbitrary two-qubit states. The theoretical explanations of some quantum channels are given by transformation operators. Furthermore, a new four-qubit entangled state quantum channel is presented.

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