Nonclassical effects in the photon-added thermal state

Abstract

It was shown recently by Lee that, if a radiation state has zero probability of having zero photon, then the state is as nonclassical as possible. This suggests that one can convert any classical state into one of the most nonclassical states simply by adding one photon to it, which can be achieved by passing an excited atom through the cavity containing the classical radiation and accepting the resultant only if the exit atom is found to be in its ground state. This concept is applied to the thermal state as an illustration.