Dynamical properties of moving atom–atom entanglement and entanglement between two atoms with optical field

Abstract

Quantum information technology largely relies on a sophisticated and fragile resource, called quantum entanglement, which exhibits a highly nontrivial manifestation of the coherent superposition of the states of composite quantum systems. In this paper, we study the interaction between the general and even coherent fields with moving and stationary two two-level atoms. In this regard, this paper investigates the von Neumann entropy and the atoms-field tangle as a measure of entanglement between the general and even coherent fields with the two atoms. Also, the entanglement between the two atoms using concurrence and negativity during time evolution is discussed. This paper examines the effects of multiphoton transitions and initial state setting on the entanglement for the system under consideration. Finally, the results demonstrate an important phenomenon such as the sudden death and birth of entanglement when the two atoms are initially in entangled states.Keywords. von Neumann entropy; concurrence; negativity; atoms-field tangle; sudden death and sudden birth of entanglement.