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arXiv · 0806.4754

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

Naoki Yamamoto·Hendra I. Nurdin·Matthew R. James·Ian R. Petersen
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Abstract

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 cavity is damped and the other is 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.

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Naoki Yamamoto, Hendra I. Nurdin, Matthew R. James, Ian R. Petersen. 2008-11-27. Avoiding entanglement sudden-death via measurement feedback control in a quantum network. https://doi.org/10.1103/physreva.78.042339

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