Mott Quantum Criticality in the Anisotropic 2D Hubbard Model
Benjamin Lenz, Salvatore R. Manmana, Thomas Pruschke, Fakher F. Assaad, Marcin Raczkowski
We present evidence for Mott quantum criticality in an anisotropic two-dimensional system of coupled Hubbard chains at half-filling. In this scenario emerging from variational cluster approximation and cluster dynamical mean-field theory, the interchain hopping t⊥ acts as control parameter driving the second-order critical endpoint Tc of the metal-insulator transition down to zero at tc⊥/t≃0.2. Below tc⊥ the volume of hole and electron Fermi pockets of a compensated metal vanishes continuously at the Mott transition. Above tc⊥ the volume reduction of the pockets is cut off by a first-order transition. We discuss the relevance of our findings to a putative quantum critical point in layered organic conductors whose location remains elusive so far.