Based on the fundamental understanding of interface electrochemistry and charging mechanism of EDL interfaces, for example the competation between electrochemistry charging and electrostatic charging, or the interfacial band alginment and band engineering confirmed with measuring working functions of different ILs by photoemmision spectroscopy (PES), we are performing the frontier research on interfacial carrier accumulation and gate induced electronic phase transitions. We are aiming to obtain electric-field-induced insulator-metal transition, insulator-superconductor transition and also carrier-mediated ferromagnetism through modulating the interfacial carrier accumulation.