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 SmCoO ₃. 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.