Fermi-Pressure-Assisted Superradiant Transition with a Mesoscopic Fermi Gas in a Cavity
Phys. Rev. Lett. 137, 193401 – Published 5 November, 2026
DOI: https://doi.org/10.1103/9bt3-cz6t
Abstract
We study the superradiant phase transition of a mesoscopic Fermi gas comprising between a few tens and a few thousand atoms in a high-finesse cavity across a wide range of densities. We observe a nonmonotonic variation of the superradiant threshold as a function of density, with a minimum reached when the Fermi and recoil wave vectors 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. Our system opens the perspective of studying few-fermion systems with strong and coherent light-matter coupling.
