Incoherent metal in the quantum critical region of SU(2) symmetric model*

Incoherent metals have recently garnered much interest in their relation to quantum criticality, high-temperature superconductivity, quantum chaos, and holography.
In this context, considerable recent interest has been devoted to the SYK model and its variants, as a paradigmatic model for metallic behaviour without quasiparticles.
With the aim at exploring the robustness of this physics beyond the large-N limit, we consider an SU(2) symmetric spin-1/2 model with disordered magnetic exchange and repulsive Hubbard local interaction, in the framework of dynamical mean-field theory. In the insulating regime, we recover the spin-glass and local moment phases of the spin-1/2 disordered Heisenberg Hamiltonian, while deep in the metallic regime we find Fermi liquid behaviour. We discuss the effect of the disordered spin coupling on the metal-insulator transition, and the presence of a quantum-critical non-Fermi liquid in the phase diagram.