It is impossible to discriminate four Bell states through local operations and classical communication (LOCC), if only one copy is provided. To complete this task, two copies will suffice and be necessary. When n copies are provided, we show that the distillable entanglement is exactly n−2.
@article{arxiv.quant-ph/0204004,
title = {The distillable entanglement of multiple copies of Bell states},
author = {Yi-Xin Chen and Dong Yang},
journal= {arXiv preprint arXiv:quant-ph/0204004},
year = {2009}
}
Comments
An argument in the original paper is replaced by a procedure of strict proof