ISIS/CMPCity Joint seminar I will discuss some new results from a joint theory-experiment collaboration on the effects of disorder on a single band Mott insulator and the emergence of a novel metallic state with a pseudogap in the density of states that persists at finite temperatures.
The system is a single crystal of the layered dichalcogenide 1T-TaS2 that is disordered without changing the carrier concentration by Cu intercalation. Angle resolved photoemission spectroscopy (ARPES) measurements reveal that increasing disorder introduces delocalized states within the Mott gap that lead to a finite conductivity, challenging conventional wisdom. Detailed theoretical analysis of the two-dimensional disordered Hubbard model shows that the novel metal is generated by the interplay of strong interaction, disorder and magnetism.
In collaboration with Elias Lahoud, K.B. Chaska and Amit Kanigel (Technion) and O. Nganba Meetei (Ohio State)