Photon bunching from an equilateral triangle of atoms

Fluorescent photon emission probability from a system of three atoms has been studied as a function of detection angles. The system under investigation consists of identical bi-level atoms forming an equilateral triangle. Only a single atom in the triangle is resonantly excited by a weak laser. The interaction mechanism among the atoms is the vacuum-mediated dipole–dipole interaction and the collective decay process. The focus is to analyse the photon pairs simultaneously radiated by the system in the far-field domain. The analysis has been done for various interatomic separations. It is seen that the interference between the photon emitters can lead to strong emission in certain directions. An intuitive understanding of the interesting directions for strong photon bunching is given. It is found that a reduction in the intensity of radiation leads to superradiance along specific directions.