Pseudogap-induced change in the nature of the Lifshitz transition in the two-dimensional Hubbard model

We study the behavior of the density of states and the B1g nematic susceptibility extracted from Raman response data across the doping-driven Lifshitz transition comparing the weak and strong interaction cases. Our results were obtained using cluster dynamical mean field theory for the two-dimensional Hubbard model. In the weakly correlated Fermi liquid regime, both quantities are approximately symmetric around the Lifshitz transition doping pLT. In the strongly correlated regime, the low-doping pseudogap leads to an asymmetric, discontinuous evolution when the Fermi surface changes from hole-like to electron-like at pLT. The Lifshitz transition thus changes character because it is tied to the pseudogap-Fermi-liquid transition. These results are consistent with available observations and should foster further experimental investigations.