The effect of a coupling field on the entanglement dynamics of a three-level atom

TL;DR

This paper investigates how a coupling laser field influences the entanglement dynamics in a three-level atom, revealing that entanglement can be controlled via the field, especially in the lower-level coupling scheme, affecting steady state entanglement.

Contribution

It demonstrates that the coupling laser field can control entanglement in a three-level atom, with distinct effects in upper- and lower-level coupling schemes, highlighting the controllability of steady state entanglement.

Findings

Entanglement can be controlled by the coupling laser field.

Only the lower-level coupling scheme shows a nonzero steady state entanglement.

The steady state entanglement depends on the laser's intensity and detuning.

Abstract

The effect of a coupling laser field on the entanglement of a three-level quantum system and its spontaneous emission is investigated via reduced quantum entropy. We consider two schemes, the upper- and lower-level couplings. By calculating the degree of entanglement (DEM) for both systems, it is shown that the entanglement between atom and its spontaneous emission can be controlled by the coupling laser field. This field, however, affects the entanglement differently in the two schemes; it is only the lower-level coupling scheme that shows a nonzero steady state DEM which can be controlled by the intensity and detuning of the coupling laser field.