Variance squeezing and entanglement of the XX central spin model

TL;DR

This paper analyzes the quantum properties of a central spin interacting with surrounding spins via Heisenberg XX couplings, deriving exact solutions and exploring variance squeezing and entanglement dynamics.

Contribution

It provides an exact solution for the dynamical operators of the XX central spin model and investigates nonclassical effects like variance squeezing and entanglement evolution.

Findings

Atomic variance exhibits revival-collapse phenomena.

Nonclassical effects are observed in all system components.

Variance squeezing and entanglement dynamics depend on detuning.

Abstract

In this paper, we study the quantum properties for a system that consists of a central atom interacting with surrounding spins through the Heisenberg $XX$ couplings of equal strength. Employing the Heisenberg equations of motion we manage to derive an exact solution for the dynamical operators. We consider that the central atom and its surroundings are initially prepared in the excited state and in the coherent spin state, respectively. For this system, we investigate the evolution of variance squeezing and entanglement. The nonclassical effects have been remarked in the behavior of all components of the system. The atomic variance can exhibit revival-collapse phenomenon based on the value of the detuning parameter.