  We study the filling-driven Mott transition involving the metallic and
paramagnetic insulating phases in SU(N) Fermi-Hubbard models, using dynamical
mean-field theory (DMFT) and the numerical renormalization group (NRG) as
impurity solver. The compressibility shows a striking temperature dependence:
near the critical temperature, it is strongly enhanced in the metallic phase
close to the insulating phase. We demonstrate that this compressibility
enhancement is associated with the thermal suppression of the quasiparticle
peak in the local spectral functions. We also explain that the asymmetric shape
of the quasiparticle peak originates from the asymmetry in the underlying
doublon-holon dynamics.
