Entanglement Measure for Pure M ⊗ N Bipartite Quantum States

Entanglement splitting of pure bipartite quantum states

where % i is a density matrix for the nth subsystem, and the positive weights pi obey ∑ i pi = 1. Otherwise the system is called entangled – a property that exists only for quantum states. Several features of entanglement have been studied so far, e.g. how to concentrate entanglement of several pairs into more entangled fewer pairs (distillation or purification [1,2]) or how to transfer entangl...

General entanglement-assisted transformation for bipartite pure quantum states

Wei Song, Yan Huang, Nai-Le Liu, and Zeng-Bing Chen 3 Hefei National Laboratory for Physical Sciences at Microscale and Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026, China Department of Computer Science and Technology, University of Science and Technology of China, Hefei, Anhui 230026, China Physikalisches Institut, Universität Heidelberg, Phi...

Measuring the entanglement of bipartite pure states

The problem of the experimental determination of the amount of entanglement of a bipartite pure state is addressed. We show that measuring a single observable does not suffice to determine the entanglement of a given unknown pure state of two particles. Possible minimal local measuring strategies are discussed and a comparison is made on the basis of their best achievable precision. PACS-number...

Entanglement of formation of bipartite quantum states.

We give an explicit tight lower bound for the entanglement of formation for arbitrary bipartite mixed states by using the convex hull construction of a certain function. This is achieved by revealing a novel connection among the entanglement of formation, the well-known Peres-Horodecki, and realignment criteria. The bound gives a quite simple and efficiently computable way to evaluate quantitat...

Detecting genuine multipartite entanglement of pure states with bipartite correlations