Quantum Correlations in Directional Emission

摘要

We examine angular distribution of the correlations of fluorescence photons emitted from a linear chain of coupled two-level atoms. Attention is focused on the simultaneous emission of correlated pairs of photons. It is found that the collective behaviour of the atoms can result in a strongly directional emission of correlated pairs of photons. The number of directions and the degree of the correlation between the photons depends strongly on whether the atoms in the chain are equally or unequally spaced. In the case of unequally spaced atoms anticorrelated pairs of photons are emitted into specific directions. For equally spaced atoms, the emitted pairs of photons are strongly correlated and highly focused into specific directions. Depending on the number of atoms, the strongly correlated pairs of photons can be emitted into well-defined single or two directions.