論文

査読有り
2016年7月

Information and backaction due to phase-contrast-imaging measurements of cold atomic gases: Beyond Gaussian states

PHYSICAL REVIEW A
  • Ebubechukwu O. Ilo-Okeke
  • ,
  • Tim Byrnes

94
1
開始ページ
013617
終了ページ
記述言語
英語
掲載種別
研究論文(学術雑誌)
DOI
10.1103/PhysRevA.94.013617
出版者・発行元
AMER PHYSICAL SOC

We further examine a theory of phase contrast imaging (PCI) of cold atomic gases, first introduced by us in Phys. Rev. Lett. 112, 233602 (2014). We model the PCI measurement by directly calculating the entangled state between the light and the atoms due to the ac Stark shift, which induces a conditional phase shift on the light depending upon the atomic state. By interfering the light that passes through the BEC with the original light, one can obtain information of the atomic state at a single-shot level. We derive an exact expression for a measurement operator that embodies the information obtained from PCI, as well as the backaction on the atomic state. By the use of exact expressions for the measurement process, we go beyond the continuous variables approximation such that the non-Gaussian regime can be accessed for both the measured state and the postmeasurement state. Features such as the photon probability density, signal, signal variance, Fisher information, error of the measurement, and the backaction are calculated by applying the measurement operator to an atomic two-spin-state system. For an atomic state that is initially in a spin-coherent state, we obtain analytical expression for these quantities. There is an optimal atom-light interaction time that scales inversely proportional to the number of atoms, which maximizes the information readout.

Web of Science ® 被引用回数 : 3

リンク情報
DOI
https://doi.org/10.1103/PhysRevA.94.013617
Web of Science
https://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=JSTA_CEL&SrcApp=J_Gate_JST&DestLinkType=FullRecord&KeyUT=WOS:000381473400010&DestApp=WOS_CPL
ID情報
  • DOI : 10.1103/PhysRevA.94.013617
  • ISSN : 2469-9926
  • eISSN : 2469-9934
  • Web of Science ID : WOS:000381473400010

エクスポート
BibTeX RIS