Initial-Phase Spectroscopy as a Control of Entangled Systems

TL;DR

This paper introduces initial-phase spectroscopy as a method to control and analyze the dynamics of entangled two-atom systems interacting with a broadband squeezed vacuum, revealing phase-dependent spectral features and entanglement phenomena.

Contribution

It presents the novel concept of initial-phase spectroscopy for controlling entangled states and demonstrates phase-dependent spectral effects and entanglement dynamics in different atomic models.

Findings

Spectral components depend on the relative phase between initial entanglement and squeezed field.

Hole burning in spectral lines correlates with entanglement sudden death.

Collective damping can rotate the phase of the squeezed field in non-Dicke models.

Abstract

We introduce the concept of initial-phase spectroscopy as a control of the dynamics of entangled states encoded into a two-atom system interacting with a broadband squeezed vacuum field. We illustrate our considerations by examining the transient spectrum of the field emitted by two systems, the small sample (Dicke) and the spatially extended (non-Dicke) models. It is found that the shape of the spectral components depends crucially on the relative phase between the initial entangled state and the squeezed field. We follow the temporal evolution of the spectrum and show that depending on the relative phase a hole burning can occur in one of the two spectral lines. We compare the transient behavior of the spectrum with the time evolution of the initial entanglement and find that the hole burning can be interpreted as a manifestation of the phenomenon of entanglement sudden death. In addition, we find that in the case of the non-Dicke model, the collective damping rate may act like an artificial tweezer that rotates the phase of the squeezed field.