In solid-state physics, the kagome metal or kagome magnet is a type of ferromagnetic quantum material. The atomic lattice in a kagome magnet has layered overlapping triangles and large hexagonal voids, akin to the kagome pattern in traditional Japanese basket-weaving.[1][2][3][4] This geometry induces a flat electronic band structure with Dirac crossings, in which the low-energy electron dynamics correlate strongly.[5]

Electrons in a kagome metal experience a "three-dimensional cousin of the quantum Hall effect": magnetic effects require electrons to flow around the kagome triangles, akin to superconductivity.[5] This phenomenon occurs in many materials at low temperatures and high external field, but, unlike superconductivity, materials are known in which the effect remains under standard conditions.[5][6]

The first room-temperature, vanishing-external-field kagome magnet discovered was the intermetallic Fe3Sn2, as shown in 2011.[7] Many others have since been found. Kagome magnets occur in a variety of crystal and magnetic structures, generally featuring a 3d-transition-metal kagome lattice with in-plane period ~5.5 Å. Examples include antiferromagnet Mn3Sn, paramagnet CoSn, ferrimagnet TbMn6Sn6, hard ferromagnet (and Weyl semimetal) Co3Sn2S2, and soft ferromagnet Fe3Sn2. Until 2019, all known kagome materials contained the heavy element tin, which has a strong spin–orbit coupling, but potential kagome materials under study (as of 2019) included magnetically doped Weyl-semimetal Co2MnGa,[8] and the class AV3Sb5 (A = Cs, Rb, K).[9] Although most research on kagome magnets has been performed on Fe3Sn2, it has since been discovered that FeSn in fact exhibits a structure much closer to the ideal kagome lattice.[10]

A kagome lattice harbors massive Dirac fermions, Berry curvature, band gaps, and spin–orbit activity, all of which are conducive to the Hall Effect and zero-energy-loss electric currents.[6][11][12] These behaviors are promising for the development of technologies in quantum computing, spin superconductors, and low power electronics.[5][6]  CsV3Sb5 in particular exhibits numerous exotic properties, including superconductivity,[13] topological states, and more.[vague][14][15][16][17] Magnetic skyrmionic bubbles have been found in Kagome metals over a wide temperature range. For example, they were observed in Fe3Sn2 at ~200-600 K using LTEM but with high critical field ~0.8 T.[18]

See also

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References

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  1. ^ Yin Jia-Xin (2018). "Giant and anisotropic many-body spin–orbit tunability in a strongly correlated kagome magnet". Nature. 562 (7725): 91–95. arXiv:1810.00218. Bibcode:2018Natur.562...91Y. doi:10.1038/s41586-018-0502-7. PMID 30209398. S2CID 205570556.
  2. ^ Li Yangmu (2019). "Magnetic-Field Control of Topological Electronic Response near Room Temperature in Correlated Kagome Magnets". Physical Review Letters. 123 (19): 196604. arXiv:1907.04948. Bibcode:2019PhRvL.123s6604L. doi:10.1103/PhysRevLett.123.196604. PMID 31765205. S2CID 195886324.
  3. ^ Khadka, Durga (2020). "Anomalous Hall and Nernst effects in epitaxial films of topological kagome magnet Fe3Sn2". Physical Review Materials. 4 (8): 084203. arXiv:2008.02202. Bibcode:2020PhRvM...4h4203K. doi:10.1103/PhysRevMaterials.4.084203. S2CID 220968766.
  4. ^ Yin Jia-Xin (2021). "Probing topological quantum matter with scanning tunnelling microscopy". Nature Reviews Physics. 3 (4): 249–263. arXiv:2103.08646. Bibcode:2021NatRP...3..249Y. doi:10.1038/s42254-021-00293-7. S2CID 232240545.
  5. ^ a b c d Jennifer Chu (March 19, 2018), "Physicists discover new quantum electronic material", MIT News, Massachusetts Institute of Technology
  6. ^ a b c "The Electronic Structure of a "Kagome" Material". ALS. 2018-06-15. Retrieved 2020-04-17.
  7. ^ Kida T (2011). "The giant anomalous Hall effect in the ferromagnet Fe3Sn2—a frustrated kagome metal". J. Phys.: Condens. Matter. 23 (11): 112205. arXiv:0911.0289. Bibcode:2011JPCM...23k2205K. doi:10.1088/0953-8984/23/11/112205. PMID 21358031. S2CID 118834551.
  8. ^ "The best of two worlds: Magnetism and Weyl semimetals". phys.org. September 2019. Retrieved 2020-04-17.
  9. ^ Ortiz, Brenden R.; Gomes, Lídia C.; Morey, Jennifer R.; Winiarski, Michal; Bordelon, Mitchell; Mangum, John S.; Oswald, Iain W. H.; Rodriguez-Rivera, Jose A.; Neilson, James R.; Wilson, Stephen D.; Ertekin, Elif; McQueen, Tyrel M.; Toberer, Eric S. (2019-09-16). "New kagome prototype materials: discovery of KV3Sb5 and CsV3Sb5". Physical Review Materials. 3 (9): 094407. doi:10.1103/PhysRevMaterials.3.094407. S2CID 204667182.
  10. ^ "MIT researchers realize "ideal" kagome metal electronic structure". MIT News. 12 December 2019. Retrieved 2020-04-17.
  11. ^ "A new 'spin' on kagome lattices". phys.org. Retrieved 2020-04-17.
  12. ^ Ye, Linda; Chan Mun K.; McDonald, Ross D.; Graf, David; Kang Mingu; Liu Junwei; Suzuki Takehito; Comin, Riccardo; Fu Liang; Checkelsky, Joseph G. (2019-10-25). "de Haas-van Alphen effect of correlated Dirac states in kagome metal Fe3Sn2". Nature Communications. 10 (1): 4870. arXiv:1809.11159. Bibcode:2019NatCo..10.4870Y. doi:10.1038/s41467-019-12822-1. ISSN 2041-1723. PMC 6814717. PMID 31653866.
  13. ^ Ortiz, Brenden R.; Teicher, Samuel M. L.; Hu Yong; Zuo, Julia L.; Sarte, Paul M.; Schueller, Emily C.; Abeykoon, A. M. Milinda; Krogstad, Matthew J.; Rosenkranz, Stephan; Osborn, Raymond; Seshadri, Ram; Balents, Leon; He, Junfeng; Wilson, Stephen D. (2020-12-10). "CsV3Sb5: A Z2 Topological Kagome Metal with a Superconducting Ground State". Physical Review Letters. 125 (24): 247002. arXiv:2011.06745. Bibcode:2020PhRvL.125x7002O. doi:10.1103/PhysRevLett.125.247002. PMID 33412053. S2CID 226955936.
  14. ^ Zhao He; Li Hong; Ortiz, Brenden R.; Teicher, Samuel M. L.; Park, Takamori; Ye Mengxing; Wang Ziqiang; Balents, Leon; Wilson, Stephen D.; Zeljkovic, Ilija (November 2021). "Cascade of correlated electron states in the kagome superconductor CsV3Sb5". Nature. 599 (7884): 216–221. arXiv:2103.03118. Bibcode:2021Natur.599..216Z. doi:10.1038/s41586-021-03946-w. ISSN 1476-4687. PMID 34587622. S2CID 232110725.
  15. ^ Guo Chunyu; Putzke, Carsten; Konyzheva, Sofia; Huang Xiangwei; Gutierrez-Amigo, Martin; Errea, Ion; Chen Dong; Vergniory, Maia G.; Felser, Claudia; Fischer, Mark H.; Neupert, Titus; Moll, Philip J. W. (2022-10-12). "Switchable chiral transport in charge-ordered kagome metal CsV3Sb5". Nature. 611 (7936): 461–466. arXiv:2203.09593. Bibcode:2022Natur.611..461G. doi:10.1038/s41586-022-05127-9. ISSN 1476-4687. PMC 9668744. PMID 36224393.
  16. ^ Jiang Yu-Xiao; Yin Jia-Xin; Denner, M. Michael; Shumiya, Nana; Ortiz, Brenden R.; Xu Gang; Guguchia, Zurab; He Junyi; Hossain, Md Shafayat; Liu Xiaoxiong; Ruff, Jacob; Kautzsch, Linus; Zhang Songtian S.; Chang Guoqing; Belopolski, Ilya (October 2021). "Unconventional chiral charge order in kagome superconductor KV3Sb5". Nature Materials. 20 (10): 1353–1357. arXiv:2012.15709. Bibcode:2021NatMa..20.1353J. doi:10.1038/s41563-021-01034-y. hdl:10356/155563. ISSN 1476-4660. PMID 34112979. S2CID 233872276.
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