Abstract
A collection of static atoms is fixed in a crystal at a low temperature and prepared by a pulse of incident radiation of wave vector . The atoms are well described by an entangled Dicke-like state, in which each atom carries a characteristic phase factor , where is the atomic position in the crystal. It is shown that a single photon absorbed by the atoms will be followed by spontaneous emission in the same direction. Furthermore, phase matched emission is found when one photon is absorbed by atoms followed by two-photon down-conversion.
- Received 12 September 2005
DOI:https://doi.org/10.1103/PhysRevLett.96.010501
©2006 American Physical Society