Non-Markovian disentanglement dynamics in double-giant-atom waveguide-QED systems

TL;DR

This paper investigates how non-Markovian effects, caused by photon transmission delays, influence the entanglement dynamics of two giant atoms in a waveguide, revealing non-exponential decay, revivals, and steady-state entanglement behaviors.

Contribution

It provides a detailed analysis of non-Markovian disentanglement dynamics in various coupling configurations of giant atoms, incorporating time delays and initial state effects.

Findings

Retardation induces non-Markovianity leading to entanglement revivals.

Steady-state entanglement depends on time delay and configuration.

Disentanglement dynamics vary with initial states and detuning effects.

Abstract

We study the disentanglement dynamics of two giant atoms coupled to a common one-dimensional waveguide. We focus on the non-Markovian retarded effect in the disentanglement of the two giant atoms by taking the photon transmission time into account. By solving the time-delayed equations of motion for the probability amplitudes, we obtain the evolution of the entanglement of the two giant atoms, which are initially in the maximally entangled states in the single-excitation space. It is found that the retardation-induced non-Markovianity leads to non-exponential decay and revivals of entanglement. Concretely, we consider separate-, braided-, and nested-coupling configurations, and find that the disentanglement dynamics in these configurations exhibits different features. We demonstrate that the steady-state entanglement depends on the time delay under certain conditions in these three coupling configurations. We also study the dependence of the disentanglement of the two giant atoms on both the detuning effect and the initial-state phase effect. In addition, we consider the disentanglement dynamics of the two giant atoms, which are initially in the state superposed by zero-excitation and two-excitation components. This work will pave the way for the generation of stationary entanglement between two giant atoms, which may have potential applications in the construction of large-scale quantum networks based on the giant-atom waveguide-QED systems.