Undamped Rabi oscillations due to polaron-emitter hybrid states in non-linear photonic wave guide coupled to emitters

TL;DR

This paper explores how two non-interacting emitters coupled to a structured waveguide can exhibit undamped Rabi oscillations due to polaron-emitter hybrid states, revealing new non-Markovian dynamics and collective effects.

Contribution

It demonstrates the emergence of undamped Rabi oscillations from polaron-emitter hybrid states in a waveguide, a novel phenomenon not seen in single-emitter systems.

Findings

Identification of parameter regimes with undamped Rabi oscillations.

Development of a two-state model capturing the full dynamics.

Discovery of all-to-all momentum space interactions between two-photon bound states.

Abstract

The collective dynamics of two non-interacting two-level emitters, which are coupled to a structured wave guide that supports two-photon bound states, is investigated. Tuning the energy of the two emitters such that they are in resonance with the two-photon bound state energy band, we identify parameter regimes where the system displays fractional populations and essentially undamped Rabi oscillations. The Rabi oscillations, which have no analog in the single-emitter dynamics, are attributed to the existence of a collective polaron-like photonic state that is induced by the emitter-photon coupling. The full dynamics is reproduced by a two-state model, in which the photonic polaron interacts with the state $|e,e,\text{vac} \rangle$ (two emitters in their excited state and empty wave guide) through a Rabi coupling frequency that depends on the emitter separation. Our work demonstrates that emitter-photon coupling can lead to an all-to-all momentum space interaction between two-photon bound states and tunable non-Markovian dynamics, opening up a new direction for emitter arrays coupled to a waveguide.