Speaker
-
Lorenzo FRATINO (LPS Orsay)
L. FRATINO: Exploring the phase diagram of the Hubbard model with several Cluster Dynamical Mean-Field Theory approaches
The Hubbard model exhibits a rich phase diagram already in the paramagnetic phase. By using continuous time quantum Monte Carlo, we study the two-dimensional Hubbard model on the square lattice with Dynamical Cluster Approximation (DCA), Cellular Dynamical Mean-Field Theory (CDMFT) and the Dimer Hubbard model on the Bethe lattice to address the unusual phenomena of the normal state. All these approaches show the Mott transition, a first order transition at half-filling between a metal and an insulator. As pointed out in previous studies with 4-site CDMFT, upon doping the insulator close to the critical Mott interaction at low temperature a pseudogap to correlated metal transition appears.
For the first time we will show that this metal to metal first order transition is not a peculiar mark of the method but is also present in the 8-site DCA DMFT. Moreover the study of the Dimer Hubbard model on the Bethe lattice (minimal cluster or multi-orbital theory possible) shows similar features creating a bridge linking the orbital selective Mott transition to the k-selective Mott transition typical of the pseudogap phase.
[1] L.Fratino, P.Sémon, G.Sordi & A.-M.S. Tremblay, Sci Rep 6, 22715(2016).
[2] L.Fratino, H.Shinaoka, Y.Nomura, L. De Medici, in preparation.
[3] L.Fratino, S.Bag, A.Camjayi, M.Civelli, M.Rozenberg, arXiv:2109.06572