J4 ›› 2010, Vol. 27 ›› Issue (2): 161-166.

• Quantum Optics • Previous Articles     Next Articles

Scheme for implementing quantum dense coding by using linear optical system

WAN Hong-Bo, YE Liu   

  1. School of Physics and Material Science, Anhui University, Hefei 230039, China
  • Published:2010-03-28 Online:2010-03-05
  • Supported by:

    National Science Foundation of China (10674001) , Important Program of the Education Department of Anhui Province ( KJ2007A002)

Abstract:

A novel scheme for realizing dense coding with Greenberger-Home-Zeilinger (GHZ) state in linear optical system is proposed. In this protocol, Alice codes on photon 1 and 2 by linear optical element and sents these photons to Bob. Then Bob will perform a joint measurement on photons 1, 2, and 3 with the GHZ basis by employing two quantum nondemolition detectors (QND) and polarizing beam splitter (PBS). Eight GHZ states can be completely discriminated. According to the outcomes of his measurement Bob can determine which operation Alice applied. Alice only transmits two photons in this process of the quantum dense coding, but Bob can obtain three bits of classical information. The QND devices are generally based on cross-Kerr nonlinearities, and the cross-Kerr nonlinearities have become available with electromagnetically induced transparency (EIT).

Key words: quantum optics, dense coding, GHZ-state, linear optical system