Coupling strongly correlated electron systems to a tunable electronic reservoir

Abstract

We study the effect of coupling an electronic reservoir to a Hubbard model and to a dimer Hubbard model. Thisis motivated by recent experiments on the effect of illumination on the insulator-metal transition in a vanadiumoxides and photoconductive cadmium sulfide heterostructure. We model the system as an electronic reservoirhybridized to the correlated system. We assume that the light intensity controls the hybridization couplingstrength. We find that the light intensity acts similarly as the temperature in the weak interaction regime. Thisis consistent with the role played by electronic reservoirs in out-of-equilibrium systems. In contrast, qualitativedifferences appear at strong coupling. We show that modeling the V2 O3 compound with a Hubbard model, ourresults describe qualitatively well the observed illumination-driven suppression of the insulator-metal transition.In contrast, in the DHM results fail to capture the mild suppression observed in the case of VO2 . This indicatesthat the lattice may play an important role in this case.