Doping-driven resistive collapse of the Mott insulator in a minimal model for VO2

LORENZO FRATINO; SOUMEN BAG; ALBERTO CAMJAYI; MARCELLO CIVELLI; MARCELO J. ROZENBERG

PHYSICAL REVIEW B

AMER PHYSICAL SOC

Lugar: New York; Año: 2022 vol. 105 p. 125140 - 125140

1098-0121

We study the resistive collapse of the Mott insulator state in the dimer Hubbard model. This minimal model has been used to describe the physics of VO2, and should be relevant to other strongly correlated materials. Itincorporates the physics of correlated dimers and the explicit competition between on-site Coulomb repulsion and magnetic exchange interactions. Our results unveil that between the Mott insulator at half filling and theFermi liquid metal at high doping there is an intermediate bad metallic phase with exotic features such as a pseudogap, orbital selectivity, and a first-order metal-metal transition. The model is solved within dynamicalmean field theory by means of quantum Monte Carlo, which provides the numerically exact solution of the model in the limit of large lattice dimensionality. This model can be considered as a minimal one that capturesexotic phenomena associated to the physics of a doped Mott insulator, shading light on their basic physical mechanism.