Direction dependent photon superbunching effect from an atomic array

Abstract

The probability of correlated emission of fluorescent photons as a function of detection directions has been investigated. The model system comprises identical two-level atoms arranged in the form of a line. A weak laser field resonantly excites only one of the atoms in the line. Two interaction mechanisms, namely, the vacuum-induced dipole–dipole interaction and the collective spontaneous emission couple the system of atoms. The aim is to observe the emission of a set of photon twins synchronized in time. It is seen that strongly directional emission of pairs of photons can take place due to the interference between the emitters. These highly correlated pairs of photons can be observed in very precise geometric directions. The observation is made based on two different detection procedures. It is found that the superradiant photons always tend to be bunched along the same direction.