Waveguide quantum electrodynamics with atomic rings around an optical nanofiber.- (Juliette Jiménez Jaimes / LCAR / Thesis). -16/10/2026, 9H

PhD defense

Juliette Jiménez Jaimes LCAR, Salle de conférence, Bat. 3R4, 9H

Abstract :
This thesis investigates the collective interaction between regular circular atomic arrays and the electromagnetic field of an optical nanofiber. The central question is how the discrete rotational symmetry of the atomic geometry, combined with the modal structure and long-range propagation of the nanofiber field, can be used to control both spontaneous emission and scattering of guided photons. For a single atomic ring, this symmetry produces mode-selective scattering: different fiber guided modes couple to different eigenmodes of the atomic ring and can consequently experience very distinct reflection and transmission spectra at the same optical frequency. For two rings, an additional exchange parity and the propagation phase accumulated between the rings control the relative coupling of the collective modes of the incident and outgoing fields. Finally, finite stacks of rings combine the previously mentioned selection rule with longitudinal interference and Bragg-type coherent build-up. They can behave as mode-selective atomic mirrors, and when two guided modes are assigned to the reflected and transmitted ports, as prototypes of two-mode photon routers.