We propose a way to measure the strength of quantum nonlocal correlation (QNC) based on the characteristic function, which is defined as a response function under the local quantum measurement in a composite system. I...We propose a way to measure the strength of quantum nonlocal correlation (QNC) based on the characteristic function, which is defined as a response function under the local quantum measurement in a composite system. It is found that the strength of QNC based on the characteristic function is a half-positive-definite function and does not change under any LU operation. Generally, we give a new definition for quantum entanglement using the strength function. Furthermore, we also give a separability-criterion for 2×m-dimensional mixed real matrix. This paper proposes an alternative way for QNC further research.展开更多
基金supported by the National Basic Research Program of China (Grant No.G2009CB929300)
文摘We propose a way to measure the strength of quantum nonlocal correlation (QNC) based on the characteristic function, which is defined as a response function under the local quantum measurement in a composite system. It is found that the strength of QNC based on the characteristic function is a half-positive-definite function and does not change under any LU operation. Generally, we give a new definition for quantum entanglement using the strength function. Furthermore, we also give a separability-criterion for 2×m-dimensional mixed real matrix. This paper proposes an alternative way for QNC further research.
