Exploring and controlling Fermi gases with light
in a high-finesse cavity
Jean-Philippe Brantut
Laboratory for Quantum Gases
EPFL, CH-1015 Lausanne, Suisse
Cavity quantum electrodynamics (QED) is one of the most powerful
framework to observe and leverage quantum phenomena. While it has
been thoroughly studied for simple quantum systems such as two-level
systems or harmonic oscillators, it has only recently become
available for complex, correlated quantum many-body systems. In the
last five years, we have developed systems combining cavity QED with
ultra-cold Fermi gases [1]. In this talk, I will describe several
intriguing consequences of the interplay of strong atom-atom and
strong light-matter coupling, such as the onset of coherent
excitations mixing Fermion-pairs and photons, pair-polaritons [2] or
the coupling of density fluctuations with light [3]. I will then
present the use of the cavity to induce long-range
interactions in a strongly-interacting Fermi gas, leading to
density-wave order, a system of direct relevance to condensed matter
physics. Last I will outline the perspectives open by the
convergence of cavity QED with Fermionic quantum matter, in
particular the possibility of programming cavity-mediated
interactions at will between atoms.
[1] K. Roux, H. Konishi, V. Helson and J.P. Brantut, Nature
Communications 11 2074 (2020)
[2] H. Konishi, K. Roux, V. Helson and J.P. Brantut, Nature 596 509
(2021)
[3] V. Helson, T. Zwettler, K. Roux, H. Konishi, S. Uchino and J.P.
Brantut arXiv:2111.02931 (2021)