Tunable Two-Dimensional Electron Gas at the Interfaces of Ferroelectric Potassium Tantalate Niobates

TL;DR

This paper reports the creation of a tunable two-dimensional electron gas at ferroelectric oxide interfaces, demonstrating electric-field control and hysteresis effects, advancing the understanding of oxide heterostructures for electronic applications.

Contribution

First demonstration of a tunable 2DEG at ferroelectric potassium tantalate niobate interfaces using amorphous LaAlO3 deposition, with electric-field modulation and hysteresis effects.

Findings

Metallic 2DEGs observed below 108 K with 11.6% resistance modulation at 7 K.

Interfaces grown under specific high-temperature and oxygen-pressure conditions exhibit good metallic conduction.

Potential for extending this behavior to other oxide-based 2DEG systems and ferroelectric metals.

Abstract

The heterointerfaces at complex oxides have emerged as a promising platform for discovering novel physical phenomena and advancing integrated sensing, storage, and computing technologies. Nevertheless, achieving precise control over a two-dimensional electron gas (2DEG) in a ferroelectric oxide-based field-effect transistor (FET) configuration remains challenging. Here, we firstly demonstrate a tunable 2DEG system fabricated by depositing an amorphous LaAlO3(LAO) film onto a (001)-oriented ferroelectric potassium tantalate niobate substrate. Interfaces grown under high-temperature and high-oxygen-pressure conditions exhibit a good metallic conduction. Notably, well-defined metallic 2DEGs displaying pronounced hysteresis and persistent electric-field-modulated resistance are observed below 108 K, achieving a resistance modulation of 11.6% at 7 K. These results underscore the potential for extending such behavior to other oxide-based 2DEG systems and facilitate further exploration of ferroelectric metals in complex oxide heterostructures.