The separability of two-mode Gaussian state under amplification and symmetric damping

The performances of a two-mode Gaussian state under parametric amplification, symmetric amplitude damping and thermal noise are studied. The time-dependent complex correlation matrix of the state in evolution is given. The separability of the final two-mode Gaussian state is examined under symmetric amplification and asymmetric amplification separately.     

Separability of Mixed States of the Quantum Network of Three Nodes

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.     

Eigenvalues, Peres＇ Separability Condition, and Entanglement

The general expression with the physical significance and positive-definite condition of the eigenvalues of 4×4 Hermitian and trace-one matrix are obtained. The obvious expression of Peres' separability condition for an arbitrary state of two qubits is then given and its operational feature is enhanced. Furthermore, we discuss some applications to the calculation of the entanglement, the upper bound of the entanglement, and a model of the transfer of entanglement in a qubit chain with noise.     

Separability Criteria for Quantum Mixed States

We investigate separability of mixed states in bipartite and multipartite quantum systems. If a quantum state in a bipartite system of arbitrary dimension (or in $2\times2\times N$ quantum systems) is separable, we show that some quantity in relation to Hermitian matrix is positive.     

粗糙有限状态机的可恢复性与连通性

利用代数的方法研究了粗糙有限状态机的可恢复性与连通性,通过前驱与后继的关系,给出了粗糙有限状态机的可恢复性、连通性与可分离性的一些刻画,讨论了粗糙有限状态机的一些基本性质.