Emergence of spinon Fermi arcs in the Weyl-Mott metal-insulator transition

The Weyl-Mott insulator (WMI) has been postulated as a novel type of correlated insulator with nontrivial topological properties. We introduce a minimal microscopic model that captures generic features of the WMI transition in Weyl semimetals. The model hosts a bulk Mott insulator with spinon Fermi arcs on its surfaces which we identify as a WMI, i.e., a $U\left(1\right)$ Weyl quantum spin liquid. At finite temperatures, we find an intermediate Weyl semimetallic phase with no quasiparticles which is consistent with the bad semimetallic behavior observed in pyrochlore iridates, $A_2{\mathrm{Ir}}_2{O}_7$, close to the Mott transition. Spinon Fermi arcs lead to a suppression of the bulk Mott gap at the surface of the WMI, in contrast to the gap enhancement expected in conventional Mott insulators, which can be detected through angular resolved photoemission spectroscopy.