English

Irreversibility of Entanglement Concentration for Pure State

Quantum Physics 2012-05-22 v1

Abstract

For a pure state ψ\psi on a composite system HAHB\mathcal{H}_A\otimes\mathcal{H}_B, both the entanglement cost EC(ψ)E_C(\psi) and the distillable entanglement ED(ψ)E_D(\psi) coincide with the von Neumann entropy H(TrBψ)H(\mathrm{Tr}_{B}\psi). Therefore, the entanglement concentration from the multiple state ψn\psi^{\otimes n} of a pure state ψ\psi to the multiple state ΦLn\Phi^{\otimes L_n} of the EPR state Φ\Phi seems to be able to be reversibly performed with an asymptotically infinitesimal error when the rate Ln/n{L_n}/{n} goes to H(TrBψ)H(\mathrm{Tr}_{B}\psi). In this paper, we show that it is impossible to reversibly perform the entanglement concentration for a multiple pure state even in asymptotic situation. In addition, in the case when we recover the multiple state ψMn\psi^{\otimes M_n} after the concentration for ψn\psi^{\otimes n}, we evaluate the asymptotic behavior of the loss number nMnn-M_n of ψ\psi. This evaluation is thought to be closely related to the entanglement compression in distant parties.

Keywords

Cite

@article{arxiv.1205.4370,
  title  = {Irreversibility of Entanglement Concentration for Pure State},
  author = {Wataru Kumagai and Masahito Hayashi},
  journal= {arXiv preprint arXiv:1205.4370},
  year   = {2012}
}

Comments

6 pages, 1 figure