Tuning of metal-insulator transition of two-dimensional electrons at parylene/SrTiO$_3$ interface by electric field

TL;DR

This paper demonstrates reversible electrostatic control of the insulator-metal transition in a 2D electron gas at the SrTiO3 interface, revealing potential for oxide electronics and superconductivity in 2D systems.

Contribution

It reports the first reversible tuning of the insulator-metal transition in 2D electrons at a SrTiO3 interface using electric fields, highlighting the potential for oxide electronic devices.

Findings

Reversible control of insulator-metal transition achieved.

Superconductivity observed beyond the transition point.

Potential for 2D metal-superconductor transition indicated.

Abstract

Electrostatic carrier doping using a field-effect-transistor structure is an intriguing approach to explore electronic phases by critical control of carrier concentration. We demonstrate the reversible control of the insulator-metal transition (IMT) in a two dimensional (2D) electron gas at the interface of insulating SrTiO$_3$ single crystals. Superconductivity was observed in a limited number of devices doped far beyond the IMT, which may imply the presence of 2D metal-superconductor transition. This realization of a two-dimensional metallic state on the most widely-used perovskite oxide is the best manifestation of the potential of oxide electronics.