Interplay between magnetism and band topology in the kagome magnets R Mn 6 Sn 6
[1];
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[1]
- Ames Laboratory (AMES), Ames, IA (United States)
- Univ. of Nebraska, Lincoln, NE (United States)
- Sophyics Technology, McLean, VA (United States)
- Ames Lab., and Iowa State Univ., Ames, IA (United States)
- Univ. of Washington, Seattle, WA (United States)
- Univ. of Delaware, Newark, DE (United States)
- State Univ. of New York (SUNY), Buffalo, NY (United States)
- Roxbury, CT (United States)
- George Mason Univ., Fairfax, VA (United States)
Kagome-lattice magnets R Mn6 Sn6 recently emerged as a new platform to exploit the interplay between magnetism and topological electronic states. Some of the most exciting features of this family are the dramatic dependence of the easy magnetization direction on the rare-earth specie, despite other magnetic and electronic properties being essentially unchanged, and the kagome geometry of the Mn planes that in principle can generate flat bands and Dirac points; gapping of the Dirac points by spin-orbit coupling has been suggested recently to be responsible for the observed anomalous Hall response in the member TbMn6 Sn6. In this paper, we address both issues with ab initio calculations. We have discovered the significant role played by higher-order crystal-field parameters and rare-earth magnetic anisotropy constants in these systems. Further, we demonstrate that the microscopic origin of rare-earth magnetic anisotropy can also be quantified and understood at various levels: ab initio, phenomenological, and analytical. In particular, using a simple and physically transparent analytical model based on perturbation theory, we are able to explain, with full quantitative agreement, the evolution of rare-earth magnetic anisotropy across the series. We analyze in detail the topological properties of Mn-dominated bands and demonstrate how they emerge from the multiorbital planar kagome model. We further show that, despite this fact, most of the topological features at the Brillouin zone corner K are strongly 3D and therefore cannot explain the observed quasi-2D anomalous Hall effect, while the most pronounced quasi-2D dispersion are too far removed from the Fermi level. By employing self-consistent calculations with ab initio many-body approaches, we demonstrate that the exchange-correlation effects beyond the density functional theory for itinerant Mn- d electrons do not significantly alter the obtained electronic and magnetic structure. Therefore, we conclude that, contrary to previous claims, the most pronounced 2D kagome-derived topological band features bear little relevance to transport in RMn6 Sn6, albeit they may possibly be brought to focus by electron or hole doping.
- Research Organization:
- Ames Laboratory (AMES), Ames, IA (United States); Lawrence Berkeley National Laboratory (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)
- Sponsoring Organization:
- USDOE Office of Science (SC), Basic Energy Sciences (BES). Materials Sciences & Engineering Division (MSE); National Science Foundation (NSF)
- Grant/Contract Number:
- AC02-07CH11358; SC0021089; OIA-2044049; DMR-2213412; AC02-05CH11231
- OSTI ID:
- 1998936
- Report Number(s):
- IS-J-11,140; TRN: US2405413
- Journal Information:
- Physical Review. B, Vol. 108, Issue 4; ISSN 2469-9950
- Publisher:
- American Physical Society (APS)Copyright Statement
- Country of Publication:
- United States
- Language:
- English
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