# Long-lived entanglement of two multilevel atoms in a waveguide

## TL;DR

This paper investigates how two multilevel quantum emitters in a waveguide can form long-lived entangled states, highlighting conditions for their existence and implications for quantum information processing.

## Contribution

It introduces a detailed analysis of bound states of multilevel emitters in waveguides and explores their potential for entanglement preservation and generation.

## Key findings

- Bound states depend on specific emitter-photon interactions
- Entanglement increases with the number of excitations
- Results are relevant for quantum communication applications

## Abstract

We study the presence of nontrivial bound states of two multilevel quantum emitters and the photons propagating in a linear waveguide. We characterize the conditions for the existence of such states and determine their general properties, focusing in particular on the entanglement between the two emitters, that increases with the number of excitations. We discuss the relevance of the results for entanglement preservation and generation by spontaneous relaxation processes.