  A generalized version of the fidelity susceptibility of single-band and
multi-orbital Hubbard models is systematically studied using single-site
dynamical mean-field theory in combination with a hybridization expansion
continuous-time quantum Monte Carlo impurity solver. We find that the fidelity
susceptibility is extremely sensitive to changes in the state of the system. It
can be used as a numerically inexpensive tool to detect and characterize a
broad range of phase transitions and crossovers in Hubbard models, including
(orbital-selective) Mott metal-insulator transitions, high-spin to low-spin
transitions, Fermi-liquid to non-Fermi-liquid crossovers, and spin-freezing
crossovers.
