Spin-orbital liquids and insulator-metal transitions on the pyrochlore lattice

The two orbital Hubbard model, with the electrons additionally coupled to a complex magnetic background, arises in pyrochlore molybdates. background involves local moments Hund's electrons, driving double exchange ferromagnetism, and antiferromagnetic (AF) tendency arising from competing superexchange. key scales include repulsion superexchange, both of which can be tuned these materials. They control phase transition ferromagnetic metal spin-glass then (Mott) insulator. We provide comprehensive description ground state this model using an unrestricted Hartree-Fock scheme implemented via simulated annealing procedure establish metal-insulator line for varying interaction see effective disorder, due frustration, already phase. disorder is further enhanced by coupling resulting disorder. As result, increasing AF shifts lower gives it additional ``Anderson'' character. detailed results on correlations, density states, optical conductivity.