Electrostatic gating of MBE-grown SrSnO₃ films using ion-gel

Electrostatic gating using ion-gel is an effective way to dynamically tune electronic phase transitions in solid materials. We report the first experimental findings of reversible electrostatic control of insulator-to-metal transition in La-doped SrSnO₃ films grown by the hybrid molecular beam epitaxy method. The low temperature sheet resistance (R_s) of the films were modulated over four orders of magnitude at an applied gate voltage of +4V. The careful analysis of the temperature dependent transport properties reveal a smooth crossover from strong-localization to weak-localization behavior at 2 K with increased positive gate voltages. We further discuss the nature of quantum corrections that are responsible for the upturn in R_s at low temperatures and its effect on the induced carrier density, on the metallic side of insulator-to-metal transition. The excellent overlap of the measured R_s (at zero gate bias) before and after multiple sequence of R_s vs T measurements at different applied gate biases indicate the true reversible and electrostatic control of the gating process in stannate systems.