title: Interfacial Multiferroics of TiO2/PbTiO3Heterostructure Driven by Ferroelectric Polarization Discontinuity.
abstract: Novel phenomena appear when two different oxide materials are combined together to form an interface. For example, at the interface of LaAlO3/SrTiO3, two-dimensional conductive states form to avoid the polar discontinuity, and magnetic properties are found at such an interface. In this work, we propose a new type of interface between two nonmagnetic and nonpolar oxides that could host a magnetic state, where it is the ferroelectric polarization discontinuity instead of the polar discontinuity that leads to the charge transfer, forming the interfacial magnetic state. As a concrete example, we investigate by first-principles calculations the heterostructures made of ferroelectric perovskite oxide PbTiO3and nonferroelectric polarized oxide TiO2. We show that charge is transferred to the interfacial layer forming an interfacial ferromagnetic ordering that may persist up to room temperature. Especially, the strong coupling between bulk ferroelectric polarization and interface ferromagnetism represents a new type of magnetoelectric effect, which provides an ideal platform for exploring the intriguing interfacial multiferroics. The findings here are important not only for fundamental science but also for promising applications in nanoscale electronics and spintronics.
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
authors.forename: Zhaohui
authors.initials: Z
authors.lastname: Ren
authors.forename: He
authors.initials: H
authors.lastname: Tian
authors.affiliation: Research Laboratory for Quantum Materials, Singapore University of Technology and Design , Singapore 487372, Singapore.
authors.forename: Shengyuan A
authors.initials: SA
authors.lastname: Yang
authors.forename: Yanwu
authors.initials: Y
authors.lastname: Xie
authors.forename: Yunhao
authors.identifier: http://orcid.org/0000-0001-6825-7206
authors.initials: Y
authors.lastname: Lu
authors.forename: Jianzhong
authors.initials: J
authors.lastname: Jiang
authors.forename: Gaorong
authors.initials: G
authors.lastname: Han
authors.affiliation: Department of NanoEngineering, University of California , San Diego, 9500 Gilman Drive, Mail Code 0448, La Jolla, California 92093-0448, United States.
authors.forename: Kesong
authors.identifier: http://orcid.org/0000-0002-9691-0636
authors.initials: K
authors.lastname: Yang
keywords: ferroelectric polarization discontinuity; first-principles; interfacial multiferroics; perovskite oxide heterostructures; spin polarization