Abstract
An assembly of noninteracting atoms may become correlated upon interaction with entangled photons, and certain elements of their joint density matrix can then show collective resonances. We explore experimental signatures of these resonances in the nonlinear response of a pair of two-level atoms. We find that these resonances are canceled out in stimulated signals such as pump-probe and two-photon absorption due to the destructive interference of two-photon-absorption and emission pathways in the joint two-particle space. However, they may be observed in photon statistics (Hanbury-Brown–Twiss) measurements through the attenuation of two-time intensity correlations.
- Received 26 January 2011
DOI:https://doi.org/10.1103/PhysRevA.83.063805
©2011 American Physical Society
