We present an improved protocol for entanglement purification of bipartite mixed states. The protocol requires two-way classical communication and hence implies an improved lower bound on the quantum capacity with two-way classical communication of the quantum depolarizing channel.
@article{arxiv.quant-ph/0702155,
title = {Entanglement purification with two-way classical communication},
author = {Alan W. Leung and Peter W. Shor},
journal= {arXiv preprint arXiv:quant-ph/0702155},
year = {2007}
}