Prediction of giant tunneling magnetoresistance in RuO2/TiO2/RuO2 (110) antiferromagnetic tunnel junctions

Authors

Yuan-Yuan Jiang, Chinese Academy of Sciences, University of Science and Technology of China
Zi-An Wang, Chinese Academy of Sciences, University of Science and Technology of China
Kartik Samanta, University of Nebraska at LincolnFollow
Shu-Hui Zhang, Beijing University of Chemical Technology
Rui-Chun Xiao, Anhui University
W. J. Lu, Chinese Academy of Sciences
Y. P. Sun, Chinese Academy of Sciences, Nanjing University
Evgeny Y. Tsymbal, University of Nebraska at LincolnFollow
Ding-Fu Shao, Chinese Academy of Sciences

Document Type

Article

Date of this Version

11-27-2023

Citation

PHYSICAL REVIEW B 108, 174439 (2023). DOI: 10.1103/PhysRevB.108.174439

Comments

Open access.

Abstract

Using first-principles quantum-transport calculations, we investigate spin-dependent electronic and transport properties of antiferromagnetic tunnel junctions (AFMTJs) that consist of (110)-oriented antiferromagnetic (AFM) metal RuO₂ electrodes and an insulating TiO₂ tunneling barrier. We predict the emergence of a giant tunneling magnetoresistance (TMR) effect in a wide energy window, a series of barrier layer thicknesses, and different interface terminations, indicating the robustness of this effect. We show that the predicted TMR cannot be explained in terms of the global transport spin-polarization of RuO₂ (110) but is well understood based on matching the momentum-dependent spin-polarized conduction channels of the two RuO₂ (110) electrodes. We predict oscillations of TMR with increasing barrier thickness, indicating a non-negligible contribution from the perfectly epitaxial interfaces. Our work helps the understanding of the physics of TMR in AFMTJs and aids in realizing efficient AFM spintronic devices.