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Model of two-dimensional electron gas formation at ferroelectric interfaces

Aguado-Puente, P., Bristowe, N. C., Yin, B., Shirasawa, R., Ghosez, Philippe, Littlewood, P. B., Artacho, Emilio (2015) Model of two-dimensional electron gas formation at ferroelectric interfaces. Physical Review B, 92 (3). ISSN 2469-9950. (doi:10.1103/PhysRevB.92.035438) (KAR id:60252)

Abstract

The formation of a two-dimensional electron gas at oxide interfaces as a consequence of polar discontinuities has generated an enormous amount of activity due to the variety of interesting effects it gives rise to. Here, we study under what circumstances similar processes can also take place underneath ferroelectric thin films. We use a simple Landau model to demonstrate that in the absence of extrinsic screening mechanisms, a monodomain phase can be stabilized in ferroelectric films by means of an electronic reconstruction. Unlike in the LaAlO3/SrTiO3 heterostructure, the emergence with thickness of the free charge at the interface is discontinuous. This prediction is confirmed by performing first-principles simulations of free-standing slabs of PbTiO3. The model is also used to predict the response of the system to an applied electric field, demonstrating that the two-dimensional electron gas can be switched on and off discontinuously and in a nonvolatile fashion. Furthermore, the reversal of the polarization can be used to switch between a two-dimensional electron gas and a two-dimensional hole gas, which should, in principle, have very different transport properties. We discuss the possible formation of polarization domains and how such configuration competes with the spontaneous accumulation of free charge at the interfaces.

Item Type: Article
DOI/Identification number: 10.1103/PhysRevB.92.035438
Subjects: Q Science > QC Physics > QC173.45 Condensed Matter
Q Science > QC Physics > QC176 Solid state physics
Q Science > QD Chemistry > QD478 Solid State Chemistry
Q Science > QD Chemistry > QD473 Physical properties in relation to structure
Divisions: Divisions > Division of Natural Sciences > Physics and Astronomy
Depositing User: Nicholas Bristowe
Date Deposited: 21 Feb 2017 16:22 UTC
Last Modified: 16 Feb 2021 13:43 UTC
Resource URI: https://kar.kent.ac.uk/id/eprint/60252 (The current URI for this page, for reference purposes)

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