Eur. Phys. J. D (2012) 66: 277
https://doi.org/10.1140/epjd/e2012-30399-2

Regular Article

Effect of thermal noise on atom-field interaction: Glauber-Lachs versus mixing

Materials Physics Division, Indira Gandhi Centre for Atomic Research, 603102 Kalpakkam, India

^a e-mail: siva@igcar.gov.in

Received: 30 June 2012
Received in final form: 12 September 2012
Published online: 30 October 2012

Abstract

Coherent signal incorporating thermal noise is a mixed state of radiation. There are two distinct classes of such states, a Gaussian state obtained by Glauber-Lachs mixing and a non-Gaussian state obtained by the canonical probabilistic mixing of thermal state and coherent state. Though both these versions are noise-included signal states, the effect of noise is less pronounced in the Glauber-Lachs version. Effects of these two distinct ways of noise addition is considered in the context of atom-field interaction; in particular, temporal evolution of population inversion and atom-field entanglement are studied. Quantum features like the collapse-revivals in the dynamics of population inversion and entanglement are diminished by the presence of thermal noise. It is shown that the features lost due to the presence of thermal noise are restored by the process of photon-addition.