Avoiding entanglement sudden death via measurement feedback control in a quantum network

Naoki Yamamoto, Hendra I. Nurdin, Matthew R. James, Ian R. Petersen

Research output: Contribution to journalArticle

59 Citations (Scopus)


In this paper, we consider a linear quantum network composed of two distantly separated cavities that are connected via a one-way optical field. When one of the cavities is damped and the other undamped, the overall cavity state obtains a large amount of entanglement in its quadratures. This entanglement, however, immediately decays and vanishes in a finite time. That is, entanglement sudden death occurs. We show that the direct measurement feedback method proposed by Wiseman can avoid this entanglement sudden death, and, further, enhance the entanglement. It is also shown that the entangled state under feedback control is robust against signal loss in a realistic detector, indicating the reliability of the proposed direct feedback method in practical situations.

Original languageEnglish
Article number042339
JournalPhysical Review A - Atomic, Molecular, and Optical Physics
Issue number4
Publication statusPublished - 2008 Oct 31


ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics

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