تقرير
Unusual Intralayer Ferromagnetism Between S = 5/2 ions in MnBi$_2$Te$_4$: Role of Empty Bi $p$ States
| العنوان: | Unusual Intralayer Ferromagnetism Between S = 5/2 ions in MnBi$_2$Te$_4$: Role of Empty Bi $p$ States |
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| المؤلفون: | Li, Jing, Ni, J. Y., Li, X. Y., Koo, H. -J., Whangbo, M. -H., Feng, J. S., Xiang, H. J. |
| المصدر: | Phys. Rev. B 101, 201408 (2020) |
| سنة النشر: | 2020 |
| المجموعة: | Condensed Matter Physics (Other) |
| مصطلحات موضوعية: | Physics - Computational Physics, Condensed Matter - Materials Science |
| الوصف: | The layered magnetic topological insulator MnBi$_2$Te$_4$ is a promising platform to realize the quantum anomalous Hall effect because its layers possess intrinsic ferromagnetism. However, it is not well understood why the high-spin $d^5$ magnetic ions Mn$^{2+}$ forming the Mn-Te-Mn spin exchange paths prefer ferromagnetic (FM) coupling, contrary to the prediction of the Goodenough-Kanamori rule that a TM-L-TM spin exchange, where TM and L are a transition-metal magnetic cation and a main group ligand, respectively, is antiferromagnetic (AFM) even when the bond angle of the exchange path is 90$^{\circ}$. Using density functional theory (DFT) calculations, we show that the presence of Bi$^{3+}$ ions is essential for the FM coupling in MnBi$_2$Te$_4$. Then, using a tight-binding model Hamiltonian, we find that high-spin $d^5$ ions (S = 5/2) in TM-L-TM spin exchange paths prefer FM coupling if the empty p-orbitals of a nonmagnetic cation M (e.g., Bi$^{3+}$ ion) hybridize strongly with those of the bridging ligand L, but AFM coupling otherwise. Comment: 13 pages, 4 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevB.101.201408 |
| URL الوصول: | http://arxiv.org/abs/2003.06585 |
| رقم الأكسشن: | edsarx.2003.06585 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevB.101.201408 |
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