title: Magnetic tunnel junctions with ferroelectric barriers: prediction of four resistance States from first principles.
abstract: Magnetic tunnel junctions (MTJs), composed of two ferromagnetic electrodes separated by a thin insulating barrier layer, are currently used in spintronic devices, such as magnetic sensors and magnetic random access memories. Recently, driven by demonstrations of ferroelectricity at the nanoscale, thin-film ferroelectric barriers were proposed to extend the functionality of MTJs. Due to the sensitivity of conductance to the magnetization alignment of the electrodes (tunneling magnetoresistance) and the polarization orientation in the ferroelectric barrier (tunneling electroresistance), these multiferroic tunnel junctions (MFTJs) may serve as four-state resistance devices. On the basis of first-principles calculations, we demonstrate four resistance states in SrRuO(3)/BaTiO(3)/SrRuO(3) MFTJs with asymmetric interfaces. We find that the resistance of such a MFTJ is significantly changed when the electric polarization of the barrier is reversed and/or when the magnetizations of the electrodes are switched from parallel to antiparallel. These results reveal the exciting prospects of MFTJs for application as multifunctional spintronic devices.
authors.affiliation: Department of Physics and Astronomy and Nebraska Center for Materials and Nanoscience, University of Nebraska, Lincoln, Nebraska 68588-0111, USA. jvelev@gmail.com
authors.forename: Julian P
authors.initials: JP
authors.lastname: Velev
authors.forename: Chun-Gang
authors.initials: CG
authors.lastname: Duan
authors.forename: J D
authors.initials: JD
authors.lastname: Burton
authors.forename: Alexander
authors.initials: A
authors.lastname: Smogunov
authors.forename: Manish K
authors.initials: MK
authors.lastname: Niranjan
authors.forename: Erio
authors.initials: E
authors.lastname: Tosatti
authors.forename: S S
authors.initials: SS
authors.lastname: Jaswal
authors.forename: Evgeny Y
authors.initials: EY
authors.lastname: Tsymbal
mesh_terms: D003198:Computer Simulation; D017097:Electric Impedance; D008280:Magnetics; D008670:Metals / Q000737:chemistry*; D008839:Microelectrodes; D008956:Models, Chemical; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size
chemical_list: D008670:Metals