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On quantum logic operations based on photon-exchange interactions in an ensemble of non-interacting atoms

M. Fleischhauer
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Abstract

The recently proposed idea to generate entanglement between photon states via exchange interactions in an ensemble of atoms (J.D. Franson and T.B. Pitman, Phys. Rev. A 60, 917 (1999) and J.D. Franson et al., (quant-ph/9912121)) is discussed using an S-matix approach. It is shown that if the nonlinear response of the atoms is negligible and no additional atom-atom interactions are present, exchange interactions cannot produce entanglement between photons states in a process that returns the atoms to their initial state. Entanglement generation requires the presence of a nonlinear atomic response or atom-atom interactions.

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M. Fleischhauer. 2000-06-08. On quantum logic operations based on photon-exchange interactions in an ensemble of non-interacting atoms. https://arxiv.org/abs/quant-ph/0006042

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