Distinct Electronic Structure of the Electrolyte Gate Induced Conducting Phase in VO$_{2}$ Revealed by Photoelectron Spectroscopy

Vanadium dioxide (VO$_{2})$, a strongly correlated material, exhibits a temperature-driven metal to insulator transition (MIT), which is accompanied by a structural transformation from rutile (high-temperature metallic phase) to monoclinic (low-temperature insulator phase). Recently, it was discovered that a low-temperature conducting state emerges in VO$_{2}$ thin films upon gating with a liquid electrolyte. In this talk, photospectroscopy measurements of the core electronic states and valence band of electrolyte gated VO$_{2}$ thin films will reveal electronic features in the gate-induced conducting phase that are distinct from those of the temperature-induced rutile metallic phase. The electronic characteristics of the gated metallic state can be accounted for by oxygen vacancy formation and a consequent reduction in V-V dimerization without lifting the orbital ordering. An electronic bandstructure taking into account these modifications will be discussed.