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Full-Text Articles in Physics
Interlayer Exchange Coupling Across A Ferroelectric Barrier, M Ye Zhuravlev, A V. Vedyayev, Evgeny Y. Tsymbal
Interlayer Exchange Coupling Across A Ferroelectric Barrier, M Ye Zhuravlev, A V. Vedyayev, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
A new magnetoelectric effect is predicted originating from the interlayer exchange coupling between two ferromagnetic layers separated by an ultrathin ferroelectric barrier. It is demonstrated that ferroelectric polarization switching driven by an external electric field leads to a sizable change in the interlayer exchange coupling. The effect occurs in asymmetric ferromagnet/ferroelectric/ferromagnet junctions due to a change in the electrostatic potential profile across the junction affecting the interlayer coupling. The predicted phenomenon indicates the possibility of switching the magnetic configuration by reversing the polarization of the ferroelectric barrier layer.
Electrically Driven Magnetism On A Pd Thin Film, Y. Sun, John D. Burton, Evgeny Y. Tsymbal
Electrically Driven Magnetism On A Pd Thin Film, Y. Sun, John D. Burton, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
Using first-principles density-functional calculations, we demonstrate that ferromagnetism can be induced and modulated on an otherwise paramagnetic Pd metal thin-film surface through application of an external electric field. As free charges are either accumulated or depleted at the Pd surface to screen the applied electric field, there is a corresponding change in the surface density of states. This change can be made sufficient for the Fermi-level density of states to satisfy the Stoner criterion, driving a transition locally at the surface from a paramagnetic state to an itinerant ferromagnetic state above a critical applied electric field, Ec. Furthermore, …
Evolution Of The Band Alignment At Polar Oxide Interfaces, John D. Burton, Evgeny Y. Tsymbal
Evolution Of The Band Alignment At Polar Oxide Interfaces, John D. Burton, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
First-principles calculations demonstrate the evolution of the band alignment at La0.7A0.3MnO3 / La1−xAxO / TiO2 / SrTiO3 (001) heterointerfaces, where A=Ca, Sr, or Ba, as the interfacial A-site composition, La1−xAx, is varied from x=0.5 to x=1.0. This variation leads to a linear change in the SrTiO3 valence-band offset with respect to the Fermi level of the La0.7A0.3MnO3 metal electrode and hence to a linear change in the Schottky barrier height at this interface. The effect arises due to electrostatic …
Effect Of Spin-Dependent Screening On Tunneling Electroresistance And Tunneling Magnetoresistance In Multiferroic Tunnel Junctions, M. Ye. Zhuravlev, S. Maekawa, Evgeny Y. Tsymbal
Effect Of Spin-Dependent Screening On Tunneling Electroresistance And Tunneling Magnetoresistance In Multiferroic Tunnel Junctions, M. Ye. Zhuravlev, S. Maekawa, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
Using a ferroelectric barrier as a functional material in a (magnetic) tunnel junction has recently attracted significant interest due to new functionalities not available in conventional tunnel junctions. Switching a ferroelectric polarization of the barrier alters conductance resulting in a tunneling electroresistance (TER) effect. Using a ferroelectric barrier in a magnetic tunnel junction makes it mutiferroic where TER coexists with tunneling magnetoresistance (TMR). Here we develop a simple model for a multiferroic tunnel junction (MFTJ) which consists of two ferromagnetic electrodes separated by a ferroelectric barrier layer. The model explicitly includes the spin-dependent screening potential and thus extends previously developed …
Ferroelectric Dead Layer Driven By A Polar Interface, Y. Wang, Manish K. Niranjan, K. Janicka, Julian P. Velev, Mikhail Ye Zhuravlev, Sitaram Jaswal, Evgeny Y. Tsymbal
Ferroelectric Dead Layer Driven By A Polar Interface, Y. Wang, Manish K. Niranjan, K. Janicka, Julian P. Velev, Mikhail Ye Zhuravlev, Sitaram Jaswal, Evgeny Y. Tsymbal
Evgeny Tsymbal Publications
Based on first-principles and model calculations we investigate the effect of polar interfaces on the ferroelectric stability of thin-film ferroelectrics. As a representative model, we consider a TiO2 -terminated BaTiO3 film with LaO monolayers at the two interfaces that serve as doping layers. We find that the polar interfaces create an intrinsic electric field that is screened by the electron charge leaking into the BaTiO3 layer. The amount of the leaking charge is controlled by the boundary conditions which are different for three heterostructures considered, namely, vacuum/LaO/BaTiO3 /LaO, LaO/BaTiO3 , and SrRuO3 /LaO/BaTiO3 …