A total measure of multi-particle quantum correlations in atomic Schr\"odinger cat states

TL;DR

This paper introduces a comprehensive measure of multi-particle quantum correlations in atomic Schrödinger cat states, analyzing how these correlations vary with atom number, initial states, and interaction time in a dispersive cavity.

Contribution

It proposes a new total measure of quantum correlations for symmetric pure states of N two-level atoms and applies it to study atomic Schrödinger cat states.

Findings

Quantum correlation increases with atom number up to N=100.

Correlation behavior varies with initial excited state population.

Interaction time influences the net quantum correlation in the system.

Abstract

We propose a total measure of multi-particle quantum correlation in a system of N two-level atoms (N qubits). We construct a parameter that encompasses all possible quantum correlations among N two-level atoms in arbitrary symmetric pure states and define its numerical value to be the total measure of the net atom-atom correlations. We use that parameter to quantify the total quantum correlations in atomic Schr\"{o}dinger cat states, which are generated by the dispersive interaction in a cavity. We study the variation of the net amount of quantum correlation as we vary the number of atoms from N=2 to N=100 and obtain some interesting results. We also study the variation of the net correlation, for fixed interaction time, as we increase the number of atoms in the excited state of the initial system, and notice some interesting features. We also observe the behaviour of the net quantum correlation as we continuously increase the interaction time, for the general state of N two-level atoms in a dispersive cavity.