We investigate the detection of entanglement in $n$ -partite quantum states. We obtain practical separability criteria to identify genuinely entangled and nonseparable mixed quantum states. No numerical optimization or eigenvalue evaluation is needed, and our criteria can be evaluated by simple computations involving components of the density matrix. We provide examples in which our criteria perform better than all known separability criteria. Specifically, we are able to detect genuine $n$ -partite entanglement which has previously not been identified. In addition, our criteria can be used in today's experiments.We investigate the detection of entanglement in $n$-partite quantum states. We obtain practical separability criteria to identify genuinely entangled and nonseparable mixed quantum states. No numerical optimization or eigenvalue evaluation is needed, and our criteria can be evaluated by simple computations involving components of the density matrix. We provide examples in which our criteria perform better than all known separability criteria. Specifically, we are able to detect genuine $n$-partite entanglement which has previously not been identified. In addition, our criteria can be used in today's experiments.

arXiv:1007.4493Physical Review ADec 14, 201049 citations

Inseparability criteria based on bipartitions of $N$ -spin systemsInseparability criteria based on bipartitions of $N$-spin systems

Asoka Biswas

We present a new set of inseparabilty inequalities to detect entanglement in $N$ -spin states. These are based on negative partial transposition and involve collective spin-spin correlations of any two partitions of the entire system. They also reveal the rich texture of partial separability for different partition and can discriminate between GHZ-type and W-type entanglement, as well. We introduce a new concept of relative entanglement of two different systems and two different partitions in a spin-ensemble. These criteria can be applicable to non-symmetric states and states with odd or even $N$ .We present a new set of inseparabilty inequalities to detect entanglement in $N$-spin states. These are based on negative partial transposition and involve collective spin-spin correlations of any two partitions of the entire system. They also reveal the rich texture of partial separability for different partition and can discriminate between GHZ-type and W-type entanglement, as well. We introduce a new concept of relative entanglement of two different systems and two different partitions in a spin-ensemble. These criteria can be applicable to non-symmetric states and states with odd or even $N$.

arXiv:1312.4462Dec 16, 20130 citations

A sufficient and necessary criterion for separability of bipartite quantum states

Zhao, Hui Hui, Yu +1 more

中国物理B：英文版Jan 1, 20140 citations

k-separability criterion of mixed multipartite quantum states

Ting Gao, Yan Hong

The $k$ -separability of mixed $n$ -partite ( $n\geq 3$ ) quantum states is mainly discussed in this paper. We obtain practical $k$ -separability criteria to identify $k$ -nonseparable mixed multipartite states in arbitrary dimensional quantum systems and detect genuine $n$ -partite entanglement ( $k=2$ ) and entanglement ( $k=3$ ) which have previously not been identified. No optimization or eigenvalue evaluation is needed, our criteria can be evaluated by simple computations involving components of the density matrix and can be implemented in today's experiments.The $k$-separability of mixed $n$-partite ($n\geq 3$) quantum states is mainly discussed in this paper. We obtain practical $k$-separability criteria to identify $k$-nonseparable mixed multipartite states in arbitrary dimensional quantum systems and detect genuine $n$-partite entanglement ($k=2$) and entanglement ($k=3$) which have previously not been identified. No optimization or eigenvalue evaluation is needed, our criteria can be evaluated by simple computations involving components of the density matrix and can be implemented in today's experiments.

Apr 13, 20122 citations

We investigate the detection of entanglement in

n

-partite quantum states. We obtain practical separability criteria to identify genuinely entangled and nonseparable mixed quantum states. No numerical optimization or eigenvalue evaluation is needed, and our criteria can be evaluated by simple computations involving components of the density matrix. We provide examples in which our criteria perform better than all known separability criteria. Specifically, we are able to detect genuine

n

-partite entanglement which has previously not been identified. In addition, our criteria can be used in today's experiments.

Inseparability criteria based on bipartitions of

N

-spin systems

We present a new set of inseparabilty inequalities to detect entanglement in

N

-spin states. These are based on negative partial transposition and involve collective spin-spin correlations of any two partitions of the entire system. They also reveal the rich texture of partial separability for different partition and can discriminate between GHZ-type and W-type entanglement, as well. We introduce a new concept of relative entanglement of two different systems and two different partitions in a spin-ensemble. These criteria can be applicable to non-symmetric states and states with odd or even

N

The

k

-separability of mixed

n

-partite (

n\geq 3

) quantum states is mainly discussed in this paper. We obtain practical

k

-separability criteria to identify

k

-nonseparable mixed multipartite states in arbitrary dimensional quantum systems and detect genuine

n

-partite entanglement (

k=2

) and entanglement (

k=3

) which have previously not been identified. No optimization or eigenvalue evaluation is needed, our criteria can be evaluated by simple computations involving components of the density matrix and can be implemented in today's experiments.