Fermi-pressure-assisted cavity superradiance in a mesoscopic Fermi gas
Abstract
We study the superradiant phase transition of a mesoscopic Fermi gas comprising between a few tens and a few thousand Li atoms in a high-finesse cavity across a wide range of densities. We observe a non-monotonic variation of the superradiant threshold as a function of density, with a minimum reached when the Fermi and recoil wavevectors are comparable. The minimum corresponds to a crossover between Fermi pressure-assisted ordering and Pauli blocking of photon scattering, in good agreement with theory. This interpretation is confirmed by a study of the atom-number dependence of the ordering threshold and photon number scaling. Lastly, we demonstrate the operation of our mesoscopic system in a regime where light-induced forces are opposite for the two spin components, leading to an ordered phase with a spin-density-wave character. Our system opens the perspective of studying few-fermion systems with strong and coherent light-matter coupling.
Cite
@article{arxiv.2603.08691,
title = {Fermi-pressure-assisted cavity superradiance in a mesoscopic Fermi gas},
author = {Francesca Orsi and Ekaterina Fedotova and Rohit Prasad Bhatt and Mae Eichenberger and Léa Dubois and Jean-Philippe Brantut},
journal= {arXiv preprint arXiv:2603.08691},
year = {2026}
}