Liquid-Gated High Mobility and Quantum Oscillation of the Two-Dimensional Electron Gas at an Oxide Interface

TL;DR

This study demonstrates that ionic liquid-assisted electric field effect can significantly enhance electron mobility at the LAO/STO oxide interface, enabling quantum oscillations and revealing potential for high-mobility oxide electronic devices.

Contribution

It introduces a method to modulate and achieve extremely high electron mobility at oxide interfaces using ionic liquids, leading to observable quantum phenomena.

Findings

Electron mobility up to 19380 cm²/Vs achieved

Quantum oscillations observed in conductivity

Ionic liquid gating effectively modulates charge carrier density

Abstract

Electric field effect in electronic double layer transistor (EDLT) configuration with ionic liquids as the dielectric materials is a powerful means of exploring various properties in different materials. Here we demonstrate the modulation of electrical transport properties and extremely high mobility of two-dimensional electron gas at LaAlO$_3$/SrTiO$_3$ (LAO/STO) interface through ionic liquid-assisted electric field effect. By changing the gate voltages, the depletion of charge carrier and the resultant enhancement of electron mobility up to 19380 cm$^2$/Vs are realized, leading to quantum oscillations of the conductivity at the LAO/STO interface. The present results suggest that high-mobility oxide interfaces which exhibit quantum phenomena could be obtained by ionic liquid-assisted field effect.