Electric-field-induced superconductivity on an organic/oxide interface

Abstract

Many superconductors have been developed by inducing charge carriers into a mother insulator compound. Chemical substitution of impurity atoms is usually used for inducing charge carriers, and this method is called "chemical doping". Another method to tune charge carrier density is the electric field effect, which is widely utilized as a field-effect transistor. Here, we review recent progress in an electric field-effect study for developing a new oxide superconductor with an organic electrolyte gate. We first present a device configuration of an electric double layer transistor with oxide semiconductors, SrTiO3 and KTaO3. We then present the electrochemical interface properties and room-temperature device characteristics with various electrolytes. Finally, we present the superconductivity emerging at an organic/oxide interface, and discuss the phase diagram of electric-field-induced superconductors by comparing with superconductors obtained by chemical doping. © 2013 The Japan Society of Applied Physics.