Natural exceptional points in the excitation spectrum of a light-matter system
Abstract
We observe natural exceptional points in the excitation spectrum of an exciton-polariton system by optically tuning the light-matter interactions. The observed exceptional points do not require any spatial or polarization degrees of freedom and result solely from the transition from weak to strong light-matter coupling. We demonstrate that they do not coincide with the threshold for photon lasing, confirming previous theoretical predictions [Phys. Rev. Lett. 122, 185301 (2019), Optica 7, 1015 (2020) ]. Using a technique where a strong coherent laser pump induces up-converted excitations, we encircle the exceptional point in the parameter space of coupling strength and particle momentum. Our method of local optical control of light-matter coupling paves the way to investigation of fundamental phenomena including dissipative phase transitions and non-Hermitian topological states.
Keywords
Cite
@article{arxiv.2306.01366,
title = {Natural exceptional points in the excitation spectrum of a light-matter system},
author = {Andrzej Opala and Magdalena Furman and Mateusz Król and Rafał Mirek and Krzysztof Tyszka and Bartłomiej Seredyński and Wojciech Pacuski and Jacek Szczytko and Michał Matuszewski and Barbara Piętka},
journal= {arXiv preprint arXiv:2306.01366},
year = {2023}
}