Correlation-Driven Eightfold Magnetic Anisotropy in a Two-Dimensional Oxide Monolayer

Published

April 10, 2020

Author(s)

Zhangzhang Cui, Alexander Grutter, Hua Zhou, Hui Cao, Yongqi Dong, Dustin A. Gilbert, Jingyuan Wang, Yi-Sheng Liu, Jiaji Ma, Zhenpeng Hu, Jinghua Guo, Jing Xia, Brian Kirby, Padraic Shafer, Elke Arenholz, Hanghui Chen, Xiaofang Zhai, Yalin Lu

Abstract

Engineering magnetic anisotropy (MA) in two-dimensional (2D) ferromagnetic materials has enormous scientific and technological implications. The uniaxial anisotropy universally exhibited by 2D ferromagnetic materials has only two stable spin directions, demanding 180 ° spin switching between states^1,2. Higher-fold symmetries with multiple magnetic easy axes enable easier spin switching, opening pathways toward low-power, multi-state spintronic devices. We have realized a correlation-driven spin reorientation transition in (SrRuO₃)₂/(SrTiO₃)_N superlattices, where the uniaxial <001> easy axis of Ru Spins in N<3 superlattices transforms into an eightfold easy axis along the <111> directions in N≥3 superlattices. This eightfold anisotropy enables 71° spin switching in 2D ferromagnetic SrRuO₃. First-principle calculations find that increasing SrTiO₃ layer thickness induces a correlation-driven orbital ordering, tuning spin-orbit interactions and reorienting the SrRuO₃ monolayer easy axis. This work reveals methods for inducing novel MA in 2D ferromagnets through digital oxide superlattice design, opening exciting opportunities for spintronic applications.

Citation

Science Advances

Volume

6

Issue

15

Pub Type

Journals

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Keywords

Ferromagnetism, Tw-dimensional, Monolayer, Thin Film, Complex Oxide, Superlattice, Perovskite, Correlated electrons

Citation

Cui, Z. , Grutter, A. , Zhou, H. , Cao, H. , Dong, Y. , Gilbert, D. , Wang, J. , Liu, Y. , Ma, J. , Hu, Z. , Guo, J. , Xia, J. , Kirby, B. , Shafer, P. , Arenholz, E. , Chen, H. , Zhai, X. and Lu, Y. (2020), Correlation-Driven Eightfold Magnetic Anisotropy in a Two-Dimensional Oxide Monolayer, Science Advances, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=927759 (Accessed April 26, 2024)