Density matrix of the superposition of excitation on coherent states with thermal light and its statistical properties

TL;DR

This paper derives the density matrix for a superposition of excitation on coherent states with thermal noise, analyzes its properties, and shows it can transmit more information than coherent light, exhibiting nonclassical features.

Contribution

It introduces a new density matrix model for SECST beams and analyzes their enhanced information capacity and nonclassicality.

Findings

SECST beam transmits more information than coherent light

The density matrix exhibits nonclassical features via the Wigner function

Information capacity increases with excitation photon number

Abstract

A beam's density matrix that is described by the superposition of excitation on coherent states with thermal noise (SECST) is presented, and its matrix elements in Fock space are calculated. The maximum information transmitted by the SECST beam is derived. It is more than that by coherent light beam and increases as the excitation photon number increases. In addition, the nonclassicality of density matrix is demonstrated by calculating its Wigner function.