Insulator-metal transition induced by electric voltage in a ruthenate Mott insulator.

We report the observation of electric-voltage induced insulator-metal phase transition in a ruthenate Mott insulator Ca(RuTi)O. We show that the electric field effect dominates and leads to a sharp phase transition at measurement temperatures far below the Mott transition, whereas the thermal effect becomes more significant and broadens the phase transition as the measurement temperature approaches the insulator-metal transition. The electric field induced insulator-metal transition is presumably attributed to the avalanche breakdown of the correlated insulating state when driven out of equilibrium. This work highlights the strategy of using electric voltage to control the phase transition of this system in addition to other nonthermal parameters such as magnetic field and pressure reported previously.