Flat band separation and robust spin Berry curvature in bilayer kagome metals
Abstract
Kagome materials have emerged as a setting for emergent electronic phenomena that encompass different aspects of symmetry and topology. It is debated whether the XV6Sn6 kagome family (where X is a rare-earth element), a recently discovered family of bilayer kagome metals, hosts a topologically non-trivial ground state resulting from the opening of spin–orbit coupling gaps. These states would carry a finite spin Berry curvature, and topological surface states. Here we investigate the spin and electronic structure of the XV6Sn6 kagome family. We obtain evidence for a finite spin Berry curvature contribution at the centre of the Brillouin zone, where the nearly flat band detaches from the dispersing Dirac band because of spin–orbit coupling. In addition, the spin Berry curvature is further investigated in the charge density wave regime of ScV6Sn6 and it is found to be robust against the onset of the temperature-driven ordered phase. Utilizing the sensitivity of angle-resolved photoemission spectroscopy to the spin and orbital angular momentum, our work unveils the spin Berry curvature of topological kagome metals and helps to define its spectroscopic fingerprint.
Citation
Di Sante , D , Bigi , C , Eck , P , Enzner , S , Consiglio , A , Pokharel , G , Carrara , P , Orgiani , P , Polewczyk , V , Fujii , J , King , P D C , Vobornik , I , Rossi , G , Zeljkovic , I , Wilson , S D , Thomale , R , Sangiovanni , G , Panaccione , G & Mazzola , F 2023 , ' Flat band separation and robust spin Berry curvature in bilayer kagome metals ' , Nature Physics . https://doi.org/10.1038/s41567-023-02053-z
Publication
Nature Physics
Status
Peer reviewed
ISSN
1745-2473Type
Journal article
Rights
Copyright © The Author(s) 2023, corrected publication 2023. This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons license and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/.
Description
Funding: The research leading to these results has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie Grant Agreement No. 897276 (D.D.S.). G.S., R.T., P.E., S.E. and A.C. are grateful for funding support from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) under Germany’s Excellence Strategy through the Würzburg-Dresden Cluster of Excellence on Complexity and Topology in Quantum Matter ct.qmat (EXC 2147, Project ID 390858490), through QUAST FOR 5249 (Project No. 449872909) as well as through the Collaborative Research Center SFB 1170 ToCoTronics (Project ID 258499086). This work has been performed in the framework of the Nanoscience Foundry and Fine Analysis (NFFA-MUR Italy Progetti Internazionali) facility (G. Panaccione and G.R.). S.D.W. and G. Pokharel acknowledge support via the UC Santa Barbara NSF Quantum Foundry funded via the Q-AMASE-i programme under award no. DMR-1906325. C.B. and P.D.C.K. gratefully acknowledge support from The Leverhulme Trust through project no. RL-2016-006. F.M. greatly acknowledges the Seal of Excellence action of PNRR (Piano Nazionale di Ripresa e Resilienza), no. SOE_0000068. We gratefully acknowledge the Gauss Centre for Supercomputing e.V. (https://www.gauss-centre.eu) for funding this project by providing computing time on the GCS Supercomputer SuperMUC-NG at Leibniz Supercomputing Centre (https://www.lrz.de ).Collections
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