Quantum Discord Dynamics for Two-Level Atom Initially in Thermal Equilibrium Interacting with n-Photon State

TL;DR

This paper studies the dynamics of quantum discord and inversion in a two-level atom interacting with a cavity field in a Fock state, revealing oscillatory behavior and beat phenomena influenced by photon number and interaction time.

Contribution

It provides an exact analysis of quantum discord evolution and inversion dynamics in the Jaynes-Cummings model with initial thermal and Fock states, highlighting oscillations and beat phenomena.

Findings

Quantum discord and inversion exhibit oscillatory behavior.

Beat phenomena are observed in both quantum discord and inversion.

Increasing photon number raises oscillation frequency.

Abstract

We investigate the quantum discord dynamics and inversion operator of a two-level atom initially in thermal equilibrium mixed state interacting with a cavity field prepared in a n-photon Fock state. We considered the Jaynes-Cummings model which is an exactly quantum mechanical model of interaction between two different quantum systems, an optical cavity in single mode n-photon Fock state and a two-level atom. The influence of interaction time and measurement basis used for calculating the conditional entropy is discussed on the evolution of the quantum discord and on its minimum. The evolution of mean value of inversion operator with interaction is also discussed. It is found that the quantum discord and inversion both shows oscillatory behaviour and also shows the phenomenon of beats with interaction time. For a given initial cavity photon Fock state the beat period of minimum quantum discord is one half of that for inversion operator. However, as the number of photons in cavity increases the frequency of oscillations of quantum discord and inversion increases.