Physics

Prof. P. Panigrahi
IISER Kolkata

Abstract: We demonstrate that light quanta of well-defined characteristics can be generated in a coupled system of three two-level atoms. The quantum nature of light is controlled by the entanglement structure, discord, and monogamy of the system, which leads to sub- and superradiant behavior, as well as sub-Poissonian statistics, at lower temperatures. Two distinct phases with different entanglement characteristics are observed with uniform radiation in one case and the other displaying highly focused and anisotropic radiation in the far-field regime. At higher temperatures, radiance witness is found to exhibit sub- and superradiant behavior of radiation intensity in the absence of entanglement albeit with non-zero quantum discord. This establishes the physical manifestation of quantum discord. It is also observed that the radiation intensity can be a precise estimator of the inter-atomic distance of a coupled system of two-level atomic systems. Our investigation shows, for the first time, the three body correlation in the form of a ‘monogamy score’ controlling the sub- and superradiant nature of radiation intensity.

Reference(s): 1. M. K. Parit, S. Ahmed, S. Singh, P. A. Lakshmi, P. K. Panigrahi, “Correlated photons of desired characteristics from a dipole coupled three-atom system”, OSA Continuum 2(8), 2293-2307 (2019).