Perfect correlations of three-particle entangled states

光太郎 上原

K. Wódkiewicz, Liwei Wang, Joseph H. Eberly

Compared to two-particle states, entangled states of three or four particles can lead to a much stronger test of local realism than is possible with Bell inequalities. It is the purpose of this paper to mention an exactly soluble quantum model in which entanglement of atomic states with cavity photon states leads to a perfectly correlated three-particle state. We demonstrate how to realize this model atom-field system and to create and observe such states, in the context of cavity quantum electrodynamics.

P. Hariharan, Joseph Samuel, Supurna Sinha

Bell's theorem reveals contradictions between the predictions of quantum mechanics and the EPR postulates for a pair of particles only in situations involving imperfect statistical correlations. However, with three or more particles, contradictions emerge even for perfect correlations. We describe an experiment which can be realized in the laboratory, using four-photon entangled states generated by parametric down-conversion, to demonstrate this contradiction at the level of perfect correlations.

Jean-Louis Basdevant, Jean Dalibard

Liwei Wang, K. Wodkiewicz, Joseph H. Eberly

We demonstrate how a new exactly soluble cavity QED model can be used to test local realism associated with three-particle entangled states, as proposed by Mermin. These states embody the correlations described by Greenberger, Horne, and Zeilinger (GHZ) and provide a stronger refutation of local hidden variable theories than is possible with Bell inequalities. It is shown that two photons distributed in the model’s four cavity modes coupled with a two-level atom can effectively produce three independent spin-1/2 particle states. We discuss preparation of the desired perfectly correlated GHZ state and a method to perform measurement on various field modes and atomic level correlations equivalent to a spin component along any direction.

Alexander Streltsov