Pseudogap in the SU(N) Fermi-Hubbard model and the Two-Particle Self-Consistent approach

Certain regimes of the cuprate phase diagram and two-dimensional Fermi-Hubbard model exhibit pseudogap behavior --- characterized by a loss of density of states near the Fermi surface. This behavior has been carefully studied due to its connection to superconductivity, antiferromagnetism and stripe order, but the physics governing it has not been clearly understood. Recently, Fermi-Hubbard quantum simulation experiments have advanced to the point of observing pseudogap behavior, allowing for new measurement techniques and tuning parameters only possible in cold atom experiments. One interesting possibility, enabled by experiments in Alkaline Earth Atoms (AEAs), would be to study pseudogap behavior in an SU(N) Fermi-Hubbard model quantum simulator (for N>2). Towards this goal, we have developed an SU(N) generalization of the Two-Particle Self-Consistent (TPSC) approach --- a method which was instrumental in establishing the existence of the weak-coupling pseudogap in the SU(2) Fermi-Hubbard model. We argue with examples that the SU(N) TPSC can be a powerful tool for understanding a broad range of experimental measurements, especially response functions of SU(N) Fermi-Hubbard models.