Search

Memristive switching serves as the basis for a new generation of electronic devices. Conventional memristors are two-terminal devices in which the current is turned on and off by redistributing point defects, e.g., vacancies. Memristors based on alternative mechanisms have been explored, but achieving both high on/off ratio and low switching energy, as needed in applications, remains a challenge. This study reports memristive switching in La0.7Ca0.3MnO3/PrBa2Cu3O7 bilayers with an on/off ratio greater than 103 and results of density functional theory calculations in terms of which it is concluded that the phenomenon is likely the result of a new type of interfacial magnetoelectricity. More specifically, this study shows that an external electric field induces subtle displacements of the interfacial Mn ions, which switches on/off an interfacial magnetic “dead layer”, resulting in memristive behavior for spin-polarized electron transport across the bilayer. The interfacial nature of the switching entails low energy cost, about of a tenth of atto Joule for writing/erasing a “bit”. The results indicate new opportunities for manganite/cuprate systems and other transition metal oxide junctions in memristive applications.

All oxide magnetic tunnel junctions based on epitaxial La0.7Ca0.3MnO3 (LCMO)(8 nm)/PrBa2Cu3O7 (PBCO) (3–8 nm)/LCMO(25–50 nm) heterostructures grown on (100) SrTiO3 are examined. Manganite electrodes show large (bulk‐like) magnetic moments and exhibit different magnetic anisotropies with different easy axes directions. A form of low dimensional magnetism is induced at the interfaces by the superexchange interaction across the reconstructed bonds. It acts as an exchange spring, driving ferromagnetic coupling between the electrodes. Resistance versus magnetic field loops demonstrate that the interfacial coupling strength depends on electric field through its effect on electronic reconstruction and orbital hierarchy at the interface. The electrically controlled magnetic coupling between the magnetic moments of the electrodes signals a new path toward low dissipation spintronics. The emergent electronic states at the interface between correlated oxides are a source of exciting novel device concepts. The induced magnetism resulting from orbital reconstruction at the barrier/electrode interfaces of a magnetic tunnel junction triggers a novel form of ferromagnetic coupling between magnetic electrodes has been showed. This coupling is electrically controlled and enables electric field switching of the magnetization, drawing a new strategy toward low dissipation spintronics. [ABSTRACT FROM AUTHOR]