English

Entanglement generation and degradation by passive optical devices

Quantum Physics 2009-11-07 v1

Abstract

The influence of losses in the interferometric generation and the transmission of continuous-variable entangled light is studied, with special emphasis on Gaussian states. Based on the theory of quantum-state transformation at absorbing dielectric devices, the amount of entanglement is quantified by means of the relative-entropy measure. Upper bounds of entanglement and the distance to the set of separable Gaussian states are calculated. Compared with the distance measure, the bounds can substantially overestimate the entanglement. In particular, they do not show the drastic decrease of entanglement with increasing mean photon number, as does the distance measure.

Keywords

Cite

@article{arxiv.quant-ph/0103167,
  title  = {Entanglement generation and degradation by passive optical devices},
  author = {Stefan Scheel and Dirk-Gunnar Welsch},
  journal= {arXiv preprint arXiv:quant-ph/0103167},
  year   = {2009}
}

Comments

11 pages, RevTeX, 11 eps figures

R2 v1 2026-07-22T19:30:38.796Z