Quantum chaos driven by long-range waveguide-mediated interactions

TL;DR

This paper investigates how long-range interactions mediated by a waveguide induce quantum chaos in photon-atom systems, revealing irregular eigenstates and breakdown of integrability, with implications for waveguide quantum electrodynamics.

Contribution

It demonstrates that waveguide-mediated long-range coupling causes quantum chaos and nonintegrability in photon-atom systems, contrasting with traditional integrable models.

Findings

Identification of irregular two-polariton eigenstates

Breakdown of Bethe ansatz due to long-range interactions

Quantum chaos emerges from waveguide-mediated coupling

Abstract

We study theoretically quantum states of a pair of photons interacting with a finite periodic array of two-level atoms in a waveguide. Our calculation reveals two-polariton eigenstates that have a highly irregular wave-function in real space. This indicates the Bethe ansatz breakdown and the onset of quantum chaos, in stark contrast to the conventional integrable problem of two interacting bosons in a box. We identify the long-range waveguide-mediated coupling between the atoms as the key ingredient of chaos and nonintegrability. Our results provide new insights in the interplay between order, chaos and localization in many-body quantum systems and can be tested in state-of-the-art setups of waveguide quantum electrodynamics.