Prediction of a Switchable Two-Dimensional Electron Gas at Ferroelectric Oxide Interfaces

Authors

Manish K. Niranjan, University of Nebraska-LincolnFollow
Yong Wang, University of Nebraska - Lincoln
Sitaram S. Jaswal, University of Nebraska - LincolnFollow
Evgeny Y. Tsymbal, University of Nebraska-LincolnFollow

Date of this Version

2009

Comments

Published in Physical Review 103, 2009. Copyright (c) 2009 The American Physical Society. Used by permission.

Abstract

The demonstration of a quasi-two-dimensional electron gas (2DEG) in LaAlO₃=SrTiO₃ heterostructures has stimulated intense research activity in recent years. The 2DEG has unique properties that are promising for applications in all-oxide electronic devices. For such applications it is desirable to have the ability to control 2DEG properties by external stimulus. Here, based on first-principles calculations we predict that all-oxide heterostructures incorporating ferroelectric constituents, such as KNbO₃=ATiO₃ (A = Sr, Ba, Pb), allow creating a 2DEG switchable between two conduction states by ferroelectric polarization reversal. The effect occurs due to the screening charge at the interface that counteracts the depolarizing electric field and depends on polarization orientation. The proposed concept of ferroelectrically controlled interface conductivity offers the possibility to design novel electronic devices.