https://doi.org/10.1140/epjd/e2014-50134-3
Regular Article
Efficient atomic and photonic multipartite W state concentration via photonic faraday rotation
1 School of Information Science and
Technology, Southwest Jiaotong University, Chengdu
610031, P.R.
China
2 State Key Laboratory of Information
Security (Graduate University of Chinese Academy of Sciences),
Beijing
100049, P.R.
China
3 School of Electronic Engineering,
Dublin City University, 9 Dublin,
Ireland
a
e-mail: luomxgg@yahoo.com.cn
Received:
21
February
2014
Received in final form:
22
April
2014
Published online:
24
July
2014
We propose entanglement concentration protocols for nonlocal W states using the Faraday rotation of photonic polarization. Through the single-photon input-output process in the cavity QED, it is shown that the maximally entangled atomic (photonic) W state can be extracted from partially entangled W state. The distinct feature of our protocol is that we can concentrate both atomic and photonic entangled states via the photonic Faraday rotation, and thus they may be useful in long distant communication in the experiment. Furthermore, since the photonic Faraday rotation works in low-Q cavities and only involves virtual excitation of atoms, our schemes are insensitive to both the cavity decay and atomic spontaneous emission.
Key words: Quantum Optics
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag 2014