Quantum correlations in two-level atomic system over Herring-Flicker coupling

TL;DR

This paper investigates how Herring-Flicker coupling affects thermal quantum correlations in tripartite two-level atomic systems, revealing controllable entanglement properties useful for quantum communication.

Contribution

It introduces the study of Herring-Flicker coupling in tripartite atomic systems with different topologies, showing how it influences quantum correlations and entanglement.

Findings

Asymmetric arrangements exhibit stronger quantum correlations.

Herring-Flicker coupling induces saturation and decay of concurrence and discord.

Controlled entanglement enhances quantum communication protocols.

Abstract

We study the thermal quantum correlations in tripartite atomic system under the existence of Herring-Flicker (HF) coupling among the atoms. We explore two topologically distinct configurations of three coupled two-level atoms, viz., loop and line, differing in their coupling pattern. Further, the systems having asymmetric arrangement of atoms are quantum mechanically correlated more strongly than systems having symmetric arrangements. The variable nature of HF coupling leads to the increase of both concurrence and discord from zero to a saturation value from where they decrease to zero as a function of inter-atomic distance. Further separation leads to both the quantities attaining another saturation value. This controlled correlations play an important role in the design of quantum data buses that can transfer quantum states to establish quantum communication. The systems coupled via HF coupling will be efficient for this task as they are maximally entangled in parametrically controlled manner. Thus, these systems will be propitious for various quantum protocols such as secure communication, quantum cryptography, quantum key distribution etc.