Probing Fermi liquid exceptional points through AC conductivity

Exceptional points, which are topological non-Hermitian degeneracies, show up in the collective mode spectrum of Fermi liquids with high angular momentum interactions. In this paper, we look for signatures these nontrivial singularities by computing AC conductivity dipolar and quadrupolar interactions a narrow slab. We that finite size slab imprints clear structures as well dephasing between electric field current density wide range coupling constants. particular, fingerprints exceptional observed weak attractive and/or regime. The main result does not depend on specific model quasiparticle also discuss some actual compounds where phenomena could be experimentally observed.