Abstract
Single atoms absorb and emit light from a resonant laser beam photon by photon. We show that a single atom strongly coupled to an optical cavity can absorb and emit resonant photons in pairs. The effect is observed in a photon correlation experiment on the light transmitted through the cavity. We find that the atom-cavity system transforms a random stream of input photons into a correlated stream of output photons, thereby acting as a two-photon gateway. The phenomenon has its origin in the quantum anharmonicity of the energy structure of the atom-cavity system. Future applications could include the controlled interaction of two photons by means of one atom.
Original language | English |
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Article number | 203602 |
Journal | Physical review letters |
Volume | 101 |
Issue number | 20 |
DOIs | |
Publication status | Published - 13 Nov 2008 |
Externally published | Yes |