arXiv subjects

M. V. Satyanarayana

Publications and source records attributed to M. V. Satyanarayana.

3 recordsLinked to original sources

arXiv2026

Pure and Mixed State Entanglement Dynamics in Tavis-Cummings Model with Squeezed Coherent Thermal States

We investigate the entanglement dynamics of two atoms interacting with a single-mode cavity field within the Tavis-Cummings model in the presence of noise. The atoms are initially prepared in either pure Bell states or mixed Werner states, allowing a direct comparison of pure- and mixed-state entanglement. The cavity field is described by generalized single-mode squeezed coherent thermal states, incorporating both thermal and quantum noise effects. Atom-atom and atom-field entanglement are quantified using concurrence and negativity, respectively. We analyze entanglement sudden death and revival, and examine how Ising-type coupling, dipole-dipole interaction, Kerr nonlinearity, and detuning modify the entanglement dynamics. Our results show that thermal photons generally suppress entanglement and enhance sudden death, while squeezing counteracts these effects. The influence of nonlinearities and interatomic interactions depends sensitively on the purity of the initial atomic state, leading to qualitatively different behaviors for Bell and Werner states.

quant-ph↗

arXiv2024

The role of thermal and squeezed photons in the entanglement dynamics of the double Jaynes-Cummings model

The effects of squeezed photons and thermal photons on the entanglement dynamics of atom-atom, atom-field and field-field subsystems are studied for the double Jaynes-Cummings model. For this purpose, squeezed coherent states and Glauber-Lachs states of radiation are chosen as field states. For the atomic states, we choose one of the Bell state as pure state and a Werner-type state as mixed state. Werner-type state is used to understand the effects of mixedness on entanglement. To measure the entanglement between the two atoms, Wootters' concurrence is used; whereas for the atom-field and field-field subsystems, negativity is chosen. The squeezed photons and thermal photons create, destroy and transfer entanglement within various subsystems. Also, the addition of squeezed photons and thermal photons either lengthens or shortens the duration of entanglement sudden deaths (ESD) associated with atom-atom, atom-field and field-field entanglement dynamics in a complementary way. The effects of Ising-type interaction, detuning and Kerr-nonlinearity on the entanglement dynamics are studied. Each of these interactions removes the ESDs associated with various subsystems. We show that new entanglements are created in this atom-field system by introducing Ising-type interaction between the two atoms. With proper choice of the parameters corresponding to Ising-type interaction, detuning and Kerr-nonliearity, entanglement can be transferred among various subsystems.

quant-ph↗

arXiv2023

Atomic Inversion and Entanglement Dynamics for Squeezed Coherent Thermal States in the Jaynes-Cummings Model

The tussling interplay between the thermal photons and the squeezed photons is discussed. The `classical noise' is represented by the thermal photons and the `quantum noise' is represented by the squeezed photons, which are pitted against each other in the background of a coherent field (represented by the coherent photons). The photon counting distribution (PCD) corresponding to the squeezed coherent thermal states are employed for this purpose. It is observed that the addition of thermal photons and squeezed photons have counterbalancing effects, by delocalizing and localizing the PCD, respectively. Various aspects of the atom-field interaction, like the atomic inversion, entanglement dynamics in the Jaynes-Cummings model have been investigated. Particular attention is given to the study of atomic inversion and entanglement dynamics due to the addition of thermal and squeezed photons to the coherent state. The interplay of thermal photons and squeezed photons have drastic effects on the PCD, atomic inversion and entanglement dynamics of the atom-field interaction.

quant-ph↗