Electrolyte-Gated SmCoO3 Thin-Film Transistors Exhibiting Thickness-Dependent Large Switching Ratio at Room Temperature

A Mott transistor that exhibits a large switching ratio of more than two orders at room temperature is demonstrated by using the electric double layer of an ionic liquid for gating on a strongly correlated electron system SmCoO3. From the thickness dependence of the on‐state channel current, we estimate the screening length of the SmCoO3 to be ∼5 nm. The good carrier confinement within the Thomas‐Fermi screening length demonstrates that the SmCoO3‐channel electric double layer transistor is the first candidate for a two‐dimensional Mott transistor.