Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Review
  • Published:

Topological kagome magnets and superconductors

Abstract

A kagome lattice naturally features Dirac fermions, flat bands and van Hove singularities in its electronic structure. The Dirac fermions encode topology, flat bands favour correlated phenomena such as magnetism, and van Hove singularities can lead to instabilities towards long-range many-body orders, altogether allowing for the realization and discovery of a series of topological kagome magnets and superconductors with exotic properties. Recent progress in exploring kagome materials has revealed rich emergent phenomena resulting from the quantum interactions between geometry, topology, spin and correlation. Here we review these key developments in this field, starting from the fundamental concepts of a kagome lattice, to the realizations of Chern and Weyl topological magnetism, to various flat-band many-body correlations, and then to the puzzles of unconventional charge-density waves and superconductivity. We highlight the connection between theoretical ideas and experimental observations, and the bond between quantum interactions within kagome magnets and kagome superconductors, as well as their relation to the concepts in topological insulators, topological superconductors, Weyl semimetals and high-temperature superconductors. These developments broadly bridge topological quantum physics and correlated many-body physics in a wide range of bulk materials and substantially advance the frontier of topological quantum matter.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Fig. 1: Fundamental concepts of kagome electrons.
Fig. 2: Chern quantum phase and spin–orbit tunability.
Fig. 3: Weyl fermion and antiferromagnetic spintronics.
Fig. 4: Flat-band correlation and many-body resonance.
Fig. 5: Charge-density wave and superconductivity.

Similar content being viewed by others

References

  1. Syôzi, I. Statistics of kagomé lattice. Prog. Theor. Phys. 6, 306–308 (1951). Introduction of the kagome lattice to quantum physics.

    Article  ADS  MathSciNet  MATH  Google Scholar 

  2. Onsager, L. et al. Crystal statistics. I. A two-dimensional model with an order–disorder transition. Phys. Rev. 65, 117–149 (1944).

    Article  ADS  MathSciNet  CAS  MATH  Google Scholar 

  3. Anderson, P. W. Resonating valence bonds: a new kind of insulator? Mater. Res. Bull. 8, 153–160 (1973).

    Article  CAS  Google Scholar 

  4. Broholm, C. et al. Quantum spin liquids. Science 367, eaay0668 (2020).

    Article  CAS  Google Scholar 

  5. Heisenberg, W. Zur Theorie des Ferromagnetismus. Z. Phys. 49, 619–636 (1928).

    Article  ADS  CAS  MATH  Google Scholar 

  6. Stoner, E. C. Collective electron ferromagnetism. Proc. R. Soc. Lond. Ser. A 165, 372–414 (1938).

    Article  ADS  MATH  Google Scholar 

  7. Mielke, A. Ferromagnetic ground states for the Hubbard model on line graphs. J. Phys. A 24, L73 (1991). Identification of electronic structure in a kagome lattice.

    Article  ADS  MathSciNet  Google Scholar 

  8. Anderson, P. W. More is different. Science 177, 393–396 (1972).

    Article  ADS  CAS  Google Scholar 

  9. Lieb, E. H. Two theorems on the Hubbard model. Phys. Rev. Lett. 62, 1201–1204 (1989).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  10. Hasan, M. Z. & Kane, C. L. Colloquium: Topological insulators. Rev. Mod. Phys. 82, 3045–3067 (2010).

    Article  ADS  CAS  Google Scholar 

  11. Qi, X.-L. & Zhang, S.-C. Topological insulators and superconductors. Rev. Mod. Phys. 83, 1057–1110 (2011).

    Article  ADS  CAS  Google Scholar 

  12. Hasan, M. Z., Xu, S.-Y. & Bian, G. Topological insulators, topological superconductors and Weyl fermion semimetals: discoveries, perspectives and outlooks. Phys. Scr. 2015, 014001 (2015).

  13. Keimer, B., Kivelson, S., Norman, M., Uchida, M. & Zaanen, J. From quantum matter to high-temperature superconductivity in copper oxides. Nature 518, 179–186 (2015).

    Article  ADS  CAS  Google Scholar 

  14. Ohgushi, K., Murakami, S. & Nagaosa, N. Spin anisotropy and quantum Hall effect in the kagomé lattice: chiral spin state based on a ferromagnet. Phys. Rev. B 62, R6065 (2000).

    Article  ADS  CAS  Google Scholar 

  15. Haldane, F. D. M. Model for a quantum Hall effect without Landau levels: condensed matter realization of the “parity anomaly”. Phys. Rev. Lett. 61, 2015–2018 (1988).

    Article  ADS  CAS  Google Scholar 

  16. Kane, C. L. & Mele, E. J. Quantum spin Hall effect in graphene. Phys. Rev. Lett. 95, 226801 (2005).

    Article  ADS  CAS  Google Scholar 

  17. Bernevig, B. A., Hughes, T. L. & Zhang, S. C. Quantum spin Hall effect and topological phase transition in HgTe quantum wells. Science 314, 1757–1761 (2006).

    Article  ADS  CAS  Google Scholar 

  18. Guo, H. M. & Franz, M. Topological insulator on the kagome lattice. Phys. Rev. B 80, 113102 (2009).

    Article  ADS  Google Scholar 

  19. Tang, E., Mei, J. W. & Wen, X. G. High-temperature fractional quantum Hall states. Phys. Rev. Lett. 106, 236802 (2011).

    Article  ADS  Google Scholar 

  20. Xu, G., Lian, B. & Zhang, S.-C. Intrinsic quantum anomalous Hall effect in the kagome lattice Cs2LiMn3F12. Phys. Rev. Lett. 115, 186802 (2015). Prediction of a kagome Chern magnet.

    Article  ADS  Google Scholar 

  21. Halperin, B. I. Possible states for a three-dimensional electron gas in a strong magnetic field. Jpn J. Appl. Phys. 26, 1913–1919 (1987).

  22. Weyl, H. Elektron und gravitation. I. Z. Phys. 56, 330–352 (1929).

    Article  ADS  MATH  Google Scholar 

  23. Wan, X., Turner, A. M., Vishwanath, A. & Savrasov, S. Y. Topological semimetal and Fermi-arc surface states in the electronic structure of pyrochlore iridates. Phys. Rev. B 83, 205101 (2011).

    Article  ADS  Google Scholar 

  24. Burkov, A. A. & Balents, L. Weyl semimetal in a topological insulator multilayer. Phys. Rev. Lett. 107, 127205 (2011).

    Article  ADS  CAS  Google Scholar 

  25. Tsui, D. C., Stormer, H. L. & Gossard, A. C. Two-dimensional magnetotransport in the extreme quantum limit. Phys. Rev. Lett. 48, 1559–1562 (1982).

    Article  ADS  CAS  Google Scholar 

  26. Laughlin, R. B. Anomalous quantum Hall effect: an incompressible quantum fluid with fractionally charged excitations. Phys. Rev. Lett. 50, 1395–1398 (1983).

    Article  ADS  Google Scholar 

  27. Qi, X.-L. Generic wave-function description of fractional quantum anomalous Hall states and fractional topological insulators. Phys. Rev. Lett. 107, 126803 (2011).

    Article  ADS  Google Scholar 

  28. Yu, S.-L. & Li, J.-X. Chiral superconducting phase and chiral spin-density-wave phase in a Hubbard model on the kagome lattice. Phys. Rev. B 85, 144402 (2012).

    Article  ADS  Google Scholar 

  29. Wang, W.-S., Li, Z.-Z., Xiang, Y.-Y. & Wang, Q.-H. Competing electronic orders on kagome lattices at van Hove filling. Phys. Rev. B 87, 115135 (2013).

    Article  ADS  Google Scholar 

  30. Kiesel, M. L., Platt, C. & Thomale, R. Unconventional Fermi surface instabilities in the kagome Hubbard model. Phys. Rev. Lett. 110, 126405 (2013).

    Article  ADS  Google Scholar 

  31. Zhu, W., Gong, S.-S., Zeng, T.-S., Fu, L. & Sheng, D. S. Interaction-driven spontaneous quantum Hall effect on a kagome lattice. Phys. Rev. Lett. 117, 096402 (2016).

    Article  ADS  CAS  Google Scholar 

  32. Varma, C. M. Non-Fermi-liquid states and pairing instability of a general model of copper oxide metals. Phys. Rev. B 55, 14554–14580 (1997).

    Article  ADS  CAS  Google Scholar 

  33. Ko, W.-H., Lee, P. A. & Wen, X.-G. Doped kagome system as exotic superconductor. Phys. Rev. B 79, 214502 (2009). Prediction of time-reversal-symmetry-breaking kagome superconductivity.

    Article  ADS  Google Scholar 

  34. Kida, T. et al. The giant anomalous Hall effect in the ferromagnet Fe3Sn2—a frustrated kagome metal. J. Phys. Condens. Matter 23, 112205 (2011). Observation of giant anomalous Hall effect in a kagome ferromagnet.

    Article  ADS  CAS  Google Scholar 

  35. Nakatsuji, S., Kiyohara, N. & Higo, T. Large anomalous Hall effect in a noncollinear antiferromagnet at room temperature. Nature 527, 212–215 (2015). Observation of room-temperature giant anomalous Hall effect in a kagome antiferromagnet.

    Article  ADS  CAS  Google Scholar 

  36. Liu, E. et al. Giant anomalous Hall effect in a ferromagnetic kagome-lattice semimetal. Nat. Phys. 14, 1125–1131 (2018).

    Article  CAS  Google Scholar 

  37. Wang, Q. et al. Large intrinsic anomalous Hall effect in half-metallic ferromagnet Co3Sn2S2 with magnetic Weyl fermions. Nat. Commun. 9, 3681 (2018).

    Article  ADS  Google Scholar 

  38. Nagaosa, N., Sinova, J., Onoda, S., MacDonald, A. H. & Ong, N. P. Anomalous Hall effect. Rev. Mod. Phys. 82, 1539–1592 (2010).

    Article  ADS  Google Scholar 

  39. Chang, C. Z. et al. Experimental observation of the quantum anomalous Hall effect in a magnetic topological insulator. Science 340, 167–170 (2013).

    Article  ADS  CAS  Google Scholar 

  40. Ye, L. et al. Massive Dirac fermions in a ferromagnetic kagome metal. Nature 555, 638–642 (2018). Observation of massive Dirac fermions in a kagome ferromagnetic metal.

    Article  ADS  CAS  Google Scholar 

  41. Yin, J. X. et al. Giant and anisotropic many-body spin–orbit tunability in a strongly correlated kagome magnet. Nature 562, 91–95 (2018). Observation of spin–orbit tunability, Berry curvature response and electronic nematicity in a kagome magnet.

    Article  ADS  CAS  Google Scholar 

  42. Fenner, L. A., Dee, A. A. & Wills, A. S. Non-collinearity and spin frustration in the itinerant kagome ferromagnet Fe3Sn2. J. Phys. Condens. Matter 21, 452202 (2009).

    Article  ADS  CAS  Google Scholar 

  43. Hou, Z. et al. Observation of various and spontaneous magnetic skyrmionic bubbles at room temperature in a frustrated kagome magnet with uniaxial magnetic anisotropy. Adv. Mater. 29, 1701144 (2017).

    Article  Google Scholar 

  44. Wang, Q., Yin, Q. & Lei, H. Giant topological Hall effect of ferromagnetic kagome metal Fe3Sn2. Chin. Phys. B 29, 017101 (2020).

    Article  ADS  CAS  Google Scholar 

  45. Li, Y. et al. Magnetic-field control of topological electronic response near room temperature in correlated kagome magnets. Phys. Rev. Lett. 123, 196604 (2019).

    Article  ADS  CAS  Google Scholar 

  46. Ye, L. et al. de Haas–van Alphen effect of correlated Dirac states in kagome metal Fe3Sn2. Nat. Commun. 10, 4870 (2019).

    Article  ADS  Google Scholar 

  47. Tanaka, H. et al. Three-dimensional electronic structure in ferromagnetic Fe3Sn2 with breathing kagome bilayers. Phys. Rev. B 101, 161114(R) (2020).

    Article  ADS  Google Scholar 

  48. Fang, S. Ferromagnetic helical nodal line and Kane–Mele spin–orbit coupling in kagome metal Fe3Sn2. Phys. Rev. B 105, 035107 (2022).

    Article  ADS  CAS  Google Scholar 

  49. Venturini, G., ElIdrissi, B. C. & Malaman, B. Magnetic properties of RMn6Sn6 (R = Sc, Y, Gd–Tm, Lu) compounds with HfFe6Ge6 type structure. J. Magn. Magn. Mater. 94, 35–42 (1991).

    Article  ADS  CAS  Google Scholar 

  50. Yin, J.-X. et al. Quantum-limit Chern topological magnetism in TbMn6Sn6. Nature 583, 533–536 (2020). Observation of a quantum-limit kagome Chern magnet with topological edge state.

    Article  ADS  CAS  Google Scholar 

  51. Ma, W. et al. Rare earth engineering in RMn6Sn6 (R = Gd–Tm, Lu) topological kagome magnets. Phys. Rev. Lett. 126, 246602 (2021).

    Article  ADS  CAS  Google Scholar 

  52. Xu, X. et al. Topological charge–entropy scaling in kagome Chern magnet TbMn6Sn6. Nat. Commun. 13, 1197 (2022).

    Article  ADS  CAS  Google Scholar 

  53. Zhang, H. et al. Exchange-biased topological transverse thermoelectric effects in a kagome ferrimagnet. Nat. Commun. 13, 1091 (2022).

    Article  ADS  CAS  Google Scholar 

  54. Mott, N. F. et al. The Theory of the Properties of Metals and Alloys (Courier Dover Publications, 1958).

  55. Wiedemann, G. & Franz, R. Relative conductivity of solids. Ann. Phys. Chem. 89, 497–531 (1853).

    Google Scholar 

  56. Asaba, T. et al. Anomalous Hall effect in the kagome ferrimagnet GdMn6Sn6. Phys. Rev. B 101, 174415 (2020).

    Article  ADS  CAS  Google Scholar 

  57. Ghimire, N. J. et al. Competing magnetic phases and fluctuation-driven scalar spin chirality in the kagome metal YMn6Sn6. Sci. Adv. 6, eabe2680 (2020).

    Article  ADS  CAS  Google Scholar 

  58. Li, M. et al. Dirac cone, flat band and saddle point in kagome magnet YMn6Sn6. Nat. Commun. 12, 3129 (2021).

    Article  ADS  CAS  Google Scholar 

  59. Wang, Q. et al. Field-induced topological Hall effect and double-fan spin structure with a c-axis component in the metallic kagome antiferromagnetic compound YMn6Sn6. Phys. Rev. B 103, 014416 (2021).

    Article  ADS  CAS  Google Scholar 

  60. Peng, S. et al. Realizing kagome band structure in two-dimensional kagome surface states of RV6Sn6 (R=Gd, Ho). Phys. Rev. Lett. 127, 266401 (2021).

    Article  ADS  CAS  Google Scholar 

  61. Li, H. et al. Manipulation of Dirac band curvature and momentum-dependent g factor in a kagome magnet. Nat. Phys. 18, 644–649 (2022). Momentum-resolved g factor in a kagome antiferromagnet.

    Article  CAS  Google Scholar 

  62. Riberolles, S. X. M. et al. Low temperature competing magnetic energy scales in the topological ferrimagnet TbMn6Sn6. Phys. Rev. X 12, 021043 (2022).

  63. Chen, D. et al. Large anomalous Hall effect in the kagome ferromagnet LiMn6Sn6. Phys. Rev. B 103, 144410 (2021).

    Article  ADS  CAS  Google Scholar 

  64. Siegfried, P. E. et al. Magnetization-driven Lifshitz transition and charge-spin coupling in the kagome metal YMn6Sn6. Commun. Phys. 5, 58 (2022).

    Article  CAS  Google Scholar 

  65. Armitage, N. P., Mele, E. J. & Vishwannath, A. Weyl and Dirac semimetals in three-dimensional solids. Rev. Mod. Phys. 90, 015001 (2018).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  66. Hasan, M. Z. et al. Weyl, Dirac and high-fold chiral fermions in topological quantum matter. Nat. Rev. Mater. 6, 784–803 (2021).

    Article  ADS  CAS  Google Scholar 

  67. Nayak, A. K. et al. Large anomalous Hall effect driven by a nonvanishing Berry curvature in the noncolinear antiferromagnet Mn3Ge. Sci. Adv. 2, e1501870 (2016).

    Article  ADS  Google Scholar 

  68. Yang, H. et al. Topological Weyl semimetals in the chiral antiferromagnetic materials Mn3Ge and Mn3Sn. New J. Phys. 19, 015008 (2017). Prediction of kagome Weyl materials.

    Article  ADS  Google Scholar 

  69. Kuroda, K. et al. Evidence for magnetic Weyl fermions in a correlated metal. Nat. Mater. 16, 1090–1095 (2017).

    Article  ADS  CAS  Google Scholar 

  70. Tomiyoshi, S. & Yamaguchi, Y. Magnetic structure and weak ferromagnetism of Mn3Sn studied by polarized neutron diffraction. J. Phys. Soc. Jpn 51, 2478–2486 (1982).

    Article  ADS  CAS  Google Scholar 

  71. Weihrich, R., Anusca, I. & Zabel, M. Half-antiperovskites: structure and type–antitype relations of shandites M3/2As (M = Co, Ni; A = In, Sn). Z. Anorg. Allg. Chem. 631, 1463–1470 (2005).

    Article  CAS  Google Scholar 

  72. Yin, J.-X. et al. Negative flat band magnetism in a spin–orbit-coupled correlated kagome magnet. Nat. Phys. 15, 443–448 (2019). Observation of topological flat-band and orbital magnetization in a kagome magnet.

    Article  CAS  Google Scholar 

  73. Zhang, S. S. et al. Many-body resonance in a correlated topological kagome antiferromagnet. Phys. Rev. Lett. 125, 046401 (2020). Observation of many-body resonance in a topological kagome magnet.

    Article  ADS  CAS  Google Scholar 

  74. Ikhlas, M. et al. Large anomalous Nernst effect at room temperature in a chiral antiferromagnet. Nat. Phys. 13, 1085–1090 (2017).

    Article  CAS  Google Scholar 

  75. Li, X. et al. Anomalous Nernst and Righi–Leduc effects in Mn3Sn: Berry curvature and entropy flow. Phys. Rev. Lett. 119, 056601 (2017).

    Article  ADS  Google Scholar 

  76. Higo, T. et al. Large magneto-optical Kerr effect and imaging of magnetic octupole domains in an antiferromagnetic metal. Nat. Photon 12, 73–78 (2018).

    Article  ADS  CAS  Google Scholar 

  77. Kimata, M. et al. Magnetic and magnetic inverse spin Hall effects in a non-collinear antiferromagnet. Nature 565, 627–630 (2019).

    Article  ADS  CAS  Google Scholar 

  78. Tsai, H. et al. Electrical manipulation of a topological antiferromagnetic state. Nature 580, 608–613 (2020). Proposal for spintronic application of a kagome Weyl magnet.

    Article  ADS  CAS  Google Scholar 

  79. Xu, L. et al. Finite-temperature violation of the anomalous transverse Wiedemann–Franz law. Sci. Adv. 6, eaaz3522 (2020).

    Article  ADS  CAS  Google Scholar 

  80. Chaudhary, G., Burkov, A. A. & Heinonen, O. G. Magnetism and magnetotransport in the kagome antiferromagnet Mn3Ge. Phys. Rev. B 105, 085108 (2022).

    Article  ADS  CAS  Google Scholar 

  81. Baltz, V. et al. Antiferromagnetic spintronics. Rev. Mod. Phys. 90, 015005 (2018).

    Article  ADS  MathSciNet  CAS  Google Scholar 

  82. Bernevig, B. A., Felser, C. & Beidenkopf, H. Progress and prospects in magnetic topological materials. Nature 603, 41–51 (2022).

    Article  ADS  CAS  Google Scholar 

  83. Guguchia, Z. et al. Tunable anomalous Hall conductivity through volume-wise magnetic competition in a topological kagome magnet. Nat. Commun. 11, 559 (2020).

    Article  ADS  CAS  Google Scholar 

  84. Liu, D. F. et al. Magnetic Weyl semimetal phase in a kagomé crystal. Science 365, 1282–1285 (2019).

    Article  ADS  CAS  Google Scholar 

  85. Morali, N. et al. Fermi-arc diversity on surface terminations of the magnetic Weyl semimetal Co3Sn2S2. Science 365, 1286–1291 (2019). Quasiparticle scattering of the surface Fermi arc states in a kagome magnet.

    Article  ADS  CAS  Google Scholar 

  86. Yin, J.-X. et al. Spin–orbit quantum impurity in a topological magnet. Nat. Commun. 11, 4415 (2020).

    Article  ADS  CAS  Google Scholar 

  87. Belopolski, I. et al. Signatures of Weyl fermion annihilation in a correlated kagome magnet. Phys. Rev. Lett. 127, 256403 (2021).

    Article  ADS  CAS  Google Scholar 

  88. Liu, D. et al. Direct observation of the spin–orbit coupling effect in magnetic Weyl semimetal Co3Sn2S2. npj Quantum Mater. 7, 11 (2022). Momentum–resolved spin–orbit gap in a kagome Weyl magnet.

    Article  ADS  CAS  Google Scholar 

  89. Chen, H., Niu, Q. & MacDonald, A. H. Anomalous Hall effect arising from noncollinear antiferromagnetism. Phys. Rev. Lett. 112, 017205 (2014).

    Article  ADS  Google Scholar 

  90. Burkov, A.  A. Anomalous Hall effect in Weyl metals. Phys. Rev. Lett. 113, 187202 (2014).

    Article  ADS  CAS  Google Scholar 

  91. Si, Q. & Steglich, F. Heavy fermions and quantum phase transitions. Science 329, 1161–1166 (2010).

    Article  ADS  CAS  Google Scholar 

  92. Bistritzer, R. & MacDonald, A. H. Moiré bands in twisted double-layer graphene. Proc. Natl Acad. Sci. USA 108, 12233–12237 (2011).

    Article  ADS  CAS  Google Scholar 

  93. Cao, Y. et al. Unconventional superconductivity in magic-angle graphene superlattices. Nature 556, 43–50 (2018).

    Article  ADS  CAS  Google Scholar 

  94. Liu, Z. H. et al. Orbital-selective Dirac fermions and extremely flat bands in frustrated kagome-lattice metal CoSn. Nat. Commun. 11, 4002 (2020).

    Article  ADS  CAS  Google Scholar 

  95. Yin, J. X. et al. Fermion–boson many-body interplay in a frustrated kagome paramagnet. Nat. Commun. 11, 4003 (2020).

    Article  ADS  CAS  Google Scholar 

  96. Kang, M. et al. Topological flat bands in frustrated kagome lattice CoSn. Nat. Commun. 11, 4004 (2020).

    Article  ADS  CAS  Google Scholar 

  97. Meier, W. R. et al. Flat bands in the CoSn-type compounds. Phys. Rev. B 102, 075148 (2020).

    Article  ADS  CAS  Google Scholar 

  98. Xie, Y. et al. Spin excitations in metallic kagome lattice FeSn and CoSn. Commun. Phys. 4, 240 (2021).

    Article  CAS  Google Scholar 

  99. Huang, H. et al. Flat-band-induced anomalous anisotropic charge transport and orbital magnetism in kagome metal CoSn. Phys. Rev. Lett. 128, 096601 (2022).

    Article  ADS  CAS  Google Scholar 

  100. Wan, S., Lu, H. & Huang, L. Temperature dependence of correlated electronic states in the archetypal kagome metal CoSn. Phys. Rev. B 105, 155131 (2022).

    Article  ADS  CAS  Google Scholar 

  101. Lin, Z. et al. Flatbands and emergent ferromagnetic ordering in Fe3Sn2 kagome lattices. Phys. Rev. Lett. 121, 096401 (2018). Kagome flat-band-induced emergent ferromagnetism.

    Article  ADS  Google Scholar 

  102. Sales, B. C. et al. Electronic, magnetic, and thermodynamic properties of the kagome layer compound FeSn. Phys. Rev. Mater. 3, 114203 (2019).

    Article  CAS  Google Scholar 

  103. Kang, M. et al. Dirac fermions and flat bands in the ideal kagome metal FeSn. Nat. Mater. 19, 163–169 (2020).

    Article  ADS  CAS  Google Scholar 

  104. Karplus, R. & Luttinger, J. M. Hall effect in ferromagnetics. Phys. Rev. 95, 1154–1160 (1954).

    Article  ADS  MATH  Google Scholar 

  105. Vanderbilt, D. in Electronic Structure Theory: Electric Polarization, Orbital Magnetization and Topological Insulators (Cambridge Univ. Press, 2018).

  106. Xing, Y. et al. Localized spin–orbit polaron in magnetic Weyl semimetal Co3Sn2S2. Nat. Commun. 11, 5613 (2020).

    Article  ADS  CAS  Google Scholar 

  107. Lin, Z. et al. Dirac fermions in antiferromagnetic FeSn kagome lattices with combined space inversion and time-reversal symmetry. Phys. Rev. B 102, 155103 (2020).

    Article  ADS  CAS  Google Scholar 

  108. Inoue, H. et al. Molecular beam epitaxy growth of antiferromagnetic kagome metal FeSn. Appl. Phys. Lett. 115, 072403 (2019).

    Article  ADS  Google Scholar 

  109. Han, M. et al. Evidence of two-dimensional flat band at the surface of antiferromagnetic kagome metal FeSn. Nat. Commun. 12, 5345 (2021).

    Article  ADS  CAS  Google Scholar 

  110. Matthias, B. T., Suhl, H. & Corenzwit, E. Ferromagnetic superconductors. Phys. Rev. Lett. 1, 449 (1958).

    Article  ADS  CAS  Google Scholar 

  111. Mielke, C. III et al. Local spectroscopic evidence for a nodeless magnetic kagome superconductor CeRu2. J. Phys. Condens. Matter 34, 485601 (2022).

  112. Ku, H. C., Meisner, G. P., Acker, F. & Johnston, D. C. Superconducting and magnetic properties of new ternary borides with the CeCo3B2-type structure. Solid State Commun. 35, 91 (1980).

    Article  ADS  CAS  Google Scholar 

  113. Mielke, C.III. et al. Nodeless kagome superconductivity in LaRu3Si2. Phys. Rev. Mater. 5, 034803 (2021).

    Article  CAS  Google Scholar 

  114. Ortiz, B. R. et al. New kagome prototype materials: discovery of KV3Sb5, RbV3Sb5, and CsV3Sb5. Phys. Rev. Mater. 3, 094407 (2019).

    Article  CAS  Google Scholar 

  115. Ortiz, B. R. et al. CsV3Sb5: a Z2 topological kagome metal with a superconducting ground state. Phys. Rev. Lett. 125, 247002 (2020). Observation of superconductivity in AV3Sb5 compounds.

    Article  ADS  CAS  Google Scholar 

  116. Ortiz, B. R. et al. Superconductivity in the Z2 kagome metal KV3Sb5. Phys. Rev. Mater. 5, 034801 (2021).

    Article  CAS  Google Scholar 

  117. Yin, Q. et al. Superconductivity and normal-state properties of kagome metal RbV3Sb5 single crystals. Chin. Phys. Lett. 38, 037403 (2021).

    Article  ADS  CAS  Google Scholar 

  118. Jiang, Y. X. et al. Unconventional chiral charge order in kagome superconductor KV3Sb5. Nat. Mater. 20, 1353–1357 (2021). Observation of 2 × 2 charge-density-wave order with magnetic response in a kagome superconductor.

    Article  ADS  CAS  Google Scholar 

  119. Li, H. et al. Observation of unconventional charge density wave without acoustic phonon anomaly in kagome superconductors AV3Sb5 (A = Rb, Cs). Phys. Rev. X 11, 031050 (2021).

    CAS  Google Scholar 

  120. Ishioka, J. et al. Chiral charge-density waves. Phys. Rev. Lett. 105, 176401 (2010).

    Article  ADS  CAS  Google Scholar 

  121. van Wezel, J. Chirality and orbital order in charge density waves. Europhys. Lett. 96, 67011 (2011).

    Article  ADS  Google Scholar 

  122. Hildebrand, B. et al. Local real-space view of the achiral 1T-TiSe2 2 × 2 × 2 charge density wave. Phys. Rev. Lett. 120, 136404 (2018).

    Article  ADS  CAS  Google Scholar 

  123. Xu, S. Y. et al. Spontaneous gyrotropic electronic order in a transition-metal dichalcogenide. Nature 578, 545–549 (2020).

    Article  ADS  CAS  Google Scholar 

  124. Liang, Z. et al. Three-dimensional charge density wave and surface-dependent vortex-core states in a kagome superconductor CsV3Sb5. Phys. Rev. X 11, 031026 (2021).

    CAS  Google Scholar 

  125. Zhao, H. et al. Cascade of correlated electron states in a kagome superconductor CsV3Sb5. Nature 599, 216–221 (2021).

    Article  ADS  CAS  Google Scholar 

  126. Chen, H. et al. Roton pair density wave in a strong-coupling kagome superconductor. Nature 599, 222–228 (2021). Observation of pair density wave in a kagome superconductor.

    Article  ADS  CAS  Google Scholar 

  127. Tan, H., Liu, Y., Wang, Z. & Yan, B. Charge density waves and electronic properties of superconducting kagome metals. Phys. Rev. Lett. 127, 046401 (2021).

    Article  ADS  CAS  Google Scholar 

  128. Miao, H. et al. Geometry of the charge density wave in the kagome metal AV3Sb5. Phys. Rev. B 104, 195132 (2021).

    Article  ADS  CAS  Google Scholar 

  129. Ratcliff, N. et al. Coherent phonon spectroscopy and interlayer modulation of charge density wave order in the kagome metal CsV3Sb5. Phys. Rev. Mater. 5, L111801 (2021).

    Article  ADS  CAS  Google Scholar 

  130. Uykur, E. et al. Optical detection of the density-wave instability in the kagome metal KV3Sb5. npj Quantum Mater. 7, 16 (2022).

    Article  ADS  Google Scholar 

  131. Xie, Y. et al. Electron–phonon coupling in the charge density wave state of CsV3Sb5. Phys. Rev. B 105, L140501 (2022).

    Article  ADS  CAS  Google Scholar 

  132. Liu, G. et al. Observation of anomalous amplitude modes in the kagome metal CsV3Sb5. Nat. Commun. 13, 3461 (2022).

    Article  ADS  CAS  Google Scholar 

  133. Luo, J. et al. Possible star-of-David pattern charge density wave with additional modulation in the kagome superconductor CsV3Sb5. npj Quantum Mater. 7, 30 (2022).

    Article  ADS  CAS  Google Scholar 

  134. Li, H. et al. Rotation symmetry breaking in the normal state of a kagome superconductor KV3Sb5. Nat. Phys. 18, 265–270 (2022).

    Article  CAS  Google Scholar 

  135. Shumiya, N. et al. Intrinsic nature of chiral charge order in the kagome superconductor RbV3Sb5. Phys. Rev. B 104, 035131 (2021).

    Article  ADS  CAS  Google Scholar 

  136. Wang, Z. et al. Electronic nature of chiral charge order in the kagome superconductor CsV3Sb5. Phys. Rev. B 104, 075148 (2021).

    Article  ADS  CAS  Google Scholar 

  137. Ortiz, B. R. et al. Fermi surface mapping and the nature of charge-density-wave order in the kagome superconductor CsV3Sb5. Phys. Rev. X 11, 041030 (2021).

    CAS  Google Scholar 

  138. Ni, S. et al. Anisotropic superconducting properties of kagome metal CsV3Sb5. Chin. Phys. Lett. 38, 057403 (2021).

    Article  ADS  CAS  Google Scholar 

  139. Xiang, Y. et al. Twofold symmetry of c-axis resistivity in topological kagome superconductor CsV3Sb5 with in-plane rotating magnetic field. Nat. Commun. 12, 6727 (2021).

    Article  ADS  CAS  Google Scholar 

  140. Nie, L. et al. Charge-density-wave-driven electronic nematicity in a kagome superconductor. Nature 604, 59–64 (2022).

    Article  ADS  CAS  Google Scholar 

  141. Liu, Z. et al. Charge-density-wave-induced bands renormalization and energy gaps in a kagome superconductor RbV3Sb5. Phys. Rev. X 11, 041010 (2021).

    CAS  Google Scholar 

  142. Nakayama, K. et al. Multiple energy scales and anisotropic energy gap in the charge-density-wave phase of the kagome superconductor CsV3Sb5. Phys. Rev. B 104, L161112 (2021).

    Article  ADS  CAS  Google Scholar 

  143. Cho, S. et al. Emergence of new van Hove singularities in the charge density wave state of a topological kagome metal RbV3Sb5. Phys. Rev. Lett. 127, 236401 (2021).

    Article  ADS  CAS  Google Scholar 

  144. Park, T., Ye, M. & Balents, L. Electronic instabilities of kagome metals: saddle points and Landau theory. Phys. Rev. B 104, 035142 (2021).

    Article  ADS  CAS  Google Scholar 

  145. Christensen, M. H., Birol, T., Andersen, B. M. & Fernandes, R. M. Theory of the charge density wave in AV3Sb5 kagome metals. Phys. Rev. B 104, 214513 (2021).

    Article  ADS  CAS  Google Scholar 

  146. Luo, H. et al. Electronic nature of charge density wave and electron–phonon coupling in kagome superconductor KV3Sb5. Nat. Commun. 13, 273 (2022).

    Article  ADS  CAS  Google Scholar 

  147. Kang, M. et al. Twofold van Hove singularity and origin of charge order in topological kagome superconductor CsV3Sb5. Nat. Phys. 18, 301–308 (2022).

    Article  CAS  Google Scholar 

  148. Song, D. et al. Orbital ordering and fluctuations in a kagome superconductor CsV3Sb5. Sci. China Phys. Mech. Astron. 65, 247462 (2022).

    Article  ADS  CAS  Google Scholar 

  149. Tazai, R., Yamakawa, Y., Onari, S. & Kontani, H. Mechanism of exotic density-wave and beyond-Migdal unconventional superconductivity in kagome metal AV3Sb5 (A = K, Rb, Cs). Sci. Adv. 8, abl4108 (2022).

    Article  ADS  Google Scholar 

  150. Neupert, T. et al. Charge order and superconductivity in kagome materials. Nat. Phys. 18, 137–143 (2022).

    Article  CAS  Google Scholar 

  151. Kenney, E., Ortiz, B., Wang, C., Wilson, S. & Graf, M. Absence of local moments in the kagome metal KV3Sb5 as determined by muon spin spectroscopy. J. Phys. Condens. Matter 33, 235801 (2021).

    Article  ADS  CAS  Google Scholar 

  152. Yang, S.-Y. et al. Giant, unconventional anomalous Hall effect in the metallic frustrated magnet candidate, KV3Sb5. Sci. Adv. 6, eabb6003 (2020).

    Article  ADS  CAS  Google Scholar 

  153. Yu, F. H. et al. Concurrence of anomalous Hall effect and charge density wave in a superconducting topological kagome metal. Phys. Rev. B 104, L041103 (2021).

    Article  ADS  CAS  Google Scholar 

  154. Feng, X., Jiang, K., Wang, Z. & Hu, J. Chiral flux phase in the kagome superconductor AV3Sb5. Sci. Bull. 66, 1384–1388 (2021).

    Article  CAS  Google Scholar 

  155. Denner, M. M., Thomale, R. & Neupert, T. Analysis of charge order in the kagome metal AV3Sb5 (A = K, Rb, Cs). Phys. Rev. Lett. 127, 217601 (2021).

    Article  ADS  CAS  Google Scholar 

  156. Lin, Y.-P. & Nandkishore, R. M. Complex charge density waves at van Hove singularity on hexagonal lattices: Haldane-model phase diagram and potential realization in the kagome metals AV3Sb5 (A=K, Rb, Cs). Phys. Rev. B 104, 045122 (2021).

    Article  ADS  CAS  Google Scholar 

  157. Mielke, C. III. et al. Time-reversal symmetry-breaking charge order in a kagome superconductor. Nature 602, 245–250 (2022). Evidence for time-reversal-symmetry-breaking charge order via a magnetic-moment-sensitive probe.

    Article  ADS  CAS  Google Scholar 

  158. Guguchia, Z. et al. Tunable nodal kagome superconductivity in charge ordered RV3Sb5. Preprint at https://arxiv.org/abs/2202.07713 (2022).

  159. Khasanov, R. et al. Charge order breaks time-reversal symmetry in CsV3Sb5. Phys. Rev. Res. 4, 023244 (2022).

    Article  CAS  Google Scholar 

  160. Xu, Y. et al. Three-state nematicity and magneto-optical Kerr effect in the charge density waves in kagome superconductors. Nat. Phys. https://doi.org/10.1038/s41567-022-01805-7 (2022).

  161. Guo, C. et al. Switchable chiral transport in charge-ordered CsV3Sb5. Nature 611, 461–466 (2022).

  162. Teng, X.-K. et al. Discovery of charge density wave in a correlated kagome lattice antiferromagnet. Nature 609, 490–495 (2022).

    Article  ADS  CAS  Google Scholar 

  163. Yin, J.-X. et al. Discovery of charge order and corresponding edge state in kagome magnet FeGe. Phys. Rev. Lett. 129, 166401 (2022).

  164. Mazin, I. I. et al. Theoretical prediction of a strongly correlated Dirac metal. Nat. Commun. 5, 4261 (2014).

    Article  ADS  CAS  Google Scholar 

  165. Yu, F. H. et al. Unusual competition of superconductivity and charge-density-wave state in a compressed topological kagome metal. Nat. Commun. 12, 3645 (2021).

    Article  ADS  CAS  Google Scholar 

  166. Chen, K. Y. et al. Double superconducting dome and triple enhancement of Tc in the kagome superconductor CsV3Sb5 under high pressure. Phys. Rev. Lett. 126, 247001 (2021).

    Article  ADS  CAS  Google Scholar 

  167. Du, F. et al. Pressure-induced double superconducting domes and charge instability in the kagome metal KV3Sb5. Phys. Rev. B 103, L220504 (2021).

    Article  ADS  CAS  Google Scholar 

  168. Song, Y. et al. Competition of superconductivity and charge density wave in selective oxidized CsV3Sb5 thin flakes. Phys. Rev. Lett. 127, 237001 (2021).

    Article  ADS  CAS  Google Scholar 

  169. Chen, X. et al. Highly robust reentrant superconductivity in CsV3Sb5 under pressure. Chin. Phys. Lett. 38, 057402 (2021).

    Article  ADS  CAS  Google Scholar 

  170. Zhu, C. C. et al. Double-dome superconductivity under pressure in the V-based kagome metals AV3Sb5 (A=Rb and K). Phys. Rev. B 105, 094507 (2022).

    Article  ADS  CAS  Google Scholar 

  171. Oey, Y. et al. Fermi level tuning and double-dome superconductivity in the kagome metals CsV3Sb5−xSnx. Phys. Rev. Mater. 6, L041801 (2022).

    Article  ADS  CAS  Google Scholar 

  172. Li, Y. et al. Tuning the competition between superconductivity and charge order in kagome superconductor Cs(V1-xNbx)3Sb5. Phys. Rev. B 105, L180507 (2022).

    Article  ADS  CAS  Google Scholar 

  173. Emery, V. J. & Kivelson, S. A. Importance of phase fluctuations in superconductors with small superfluid density. Nature 374, 434–437 (1995).

    Article  ADS  CAS  Google Scholar 

  174. Mu, C. et al. S-wave superconductivity in kagome metal CsV3Sb5 revealed by 121/123Sb NQR and 51V NMR measurements. Chin. Phys. Lett. 38, 077402 (2021).

    Article  ADS  CAS  Google Scholar 

  175. Gupta, R. et al. Microscopic evidence for anisotropic multigap superconductivity in the CsV3Sb5 kagome superconductor. npj Quantum Mater. 7, 49 (2022).

    Article  ADS  CAS  Google Scholar 

  176. Wu, X. et al. Nature of unconventional pairing in the kagome superconductors AV3Sb5 (A = K, Rb, Cs). Phys. Rev. Lett. 127, 177001 (2021).

    Article  ADS  CAS  Google Scholar 

  177. Xu, H.-S. et al. Multiband superconductivity with sign-preserving order parameter in kagome superconductor CsV3Sb5. Phys. Rev. Lett. 127, 187004 (2021).

    Article  ADS  CAS  Google Scholar 

  178. Duan, W. et al. Nodeless superconductivity in the kagome metal CsV3Sb5. Sci. China Phys. Mech. Astron. 64, 107462 (2021).

    Article  ADS  CAS  Google Scholar 

  179. Gu, Y. et al. Gapless excitations inside the fully gapped kagome superconductors AV3Sb5. Phys. Rev. B 105, L100502 (2022).

    Article  ADS  CAS  Google Scholar 

  180. Lou, R. et al. Charge-density-wave-induced peak–dip–hump structure and the multiband superconductivity in a kagome superconductor CsV3Sb5. Phys. Rev. Lett. 128, 036402 (2022).

    Article  ADS  CAS  Google Scholar 

  181. Keimer, B. & Moore, J. The physics of quantum materials. Nat. Phys. 13, 1045–1055 (2017).

    Article  CAS  Google Scholar 

  182. Gao, Z.-A. Design and synthesis of a single-layer ferromagnetic metal−organic framework with topological nontrivial gaps. J. Phys. Chem. C 124, 27017–27023 (2020).

    Article  CAS  Google Scholar 

  183. Fuchs, M. et al. Kagome metal–organic frameworks as a platform for strongly correlated electrons. J. Phys. Mater. 3, 025001 (2020).

    Article  CAS  Google Scholar 

  184. Asaba, T. et al. Colossal anomalous Nernst effect in a correlated noncentrosymmetric kagome ferromagnet. Sci. Adv. 7, abf1467 (2021).

    Article  ADS  Google Scholar 

  185. Chen, T. et al. Large anomalous Nernst effect and nodal plane in an iron-based kagome ferromagnet. Sci. Adv. 8, abk1480 (2022).

    Article  ADS  Google Scholar 

  186. Muechler, L. et al. Emerging chiral edge states from the confinement of a magnetic Weyl semimetal in Co3Sn2S2. Phys. Rev. B 101, 115106 (2020).

    Article  ADS  CAS  Google Scholar 

  187. Howard, S. et al. Evidence for one-dimensional chiral edge states in a magnetic Weyl semimetal Co3Sn2S2. Nat. Commun. 12, 4269 (2021).

    Article  ADS  CAS  Google Scholar 

  188. Regnault, N. et al. Catalogue of flat-band stoichiometric materials. Nature 603, 824–828 (2022).

    Article  ADS  CAS  Google Scholar 

  189. Rhim, J. W., Kim, K. & Yang, B. J. Quantum distance and anomalous Landau levels of flat bands. Nature 584, 59–63 (2020).

    Article  ADS  CAS  Google Scholar 

  190. Nayak, C., Simon, S. H., Stern, A., Freedman, M. & Sarma, S. D. Non-Abelian anyons and topological quantum computation. Rev. Mod. Phys. 80, 1083 (2008).

    Article  ADS  MathSciNet  CAS  MATH  Google Scholar 

  191. Lian, B., Sun, X.-Q., Vaezi, A., Qi, X.-L. & Zhang, S.-C. Topological quantum computation based on chiral Majorana fermions. Proc. Natl Acad. Sci. USA 115, 10938–10942 (2018).

    Article  ADS  MathSciNet  CAS  MATH  Google Scholar 

  192. Yan, S., Huse, D. A. & White, S. R. Spin-liquid ground state of the S=1/2 kagome Heisenberg antiferromagnet. Science 332, 1173–1176 (2011).

    Article  ADS  CAS  Google Scholar 

  193. He, Y.-C., Zaletel, M. P., Oshikawa, M. & Pollmann, F. Signatures of dirac cones in a DMRG study of the kagome Heisenberg model. Phys. Rev. X 7, 031020 (2017).

    Google Scholar 

  194. Laughlin, R. B. Superconducting ground state of noninteracting particles obeying fractional statistics. Phys. Rev. Lett. 60, 2677–2680 (1988).

    Article  ADS  CAS  Google Scholar 

  195. Kalmeyer, V. & Laughlin, R. B. Theory of the spin liquid state of the Heisenberg antiferromagnet. Phys. Rev. B 39, 11879–11899 (1989).

    Article  ADS  CAS  Google Scholar 

  196. Kasahara, Y. et al. Majorana quantization and half-integer thermal quantum Hall effect in a Kitaev spin liquid. Nature 559, 227–231 (2018).

    Article  ADS  CAS  Google Scholar 

  197. Czajka, P. et al. Oscillations of the thermal conductivity in the spin-liquid state of α-RuCl3. Nat. Phys. 17, 915–919 (2021).

    Article  CAS  Google Scholar 

  198. Di Sante, D. et al. Turbulent hydrodynamics in strongly correlated kagome metals. Nat. Commun. 11, 3997 (2020).

    Article  ADS  Google Scholar 

  199. Lima, F. C. Double flat bands in kagome twisted bilayers. Phys. Rev. B 100, 155421 (2019).

    Article  ADS  Google Scholar 

  200. Scheer, M. G., Gu, K. & Lian, B. Magic angles in twisted bilayer graphene near commensuration: towards a hypermagic regime. Phys. Rev. B 106, 115418 (2022).

    Article  ADS  CAS  Google Scholar 

Download references

Acknowledgements

We thank our research collaborators for various discussions on kagome physics. M.Z.H. acknowledges support from the US Department of Energy, Office of Science, National Quantum Information Science Research Centers, Quantum Science Center and Princeton University; visiting scientist support at Berkeley Lab (Lawrence Berkeley National Laboratory) during the early phases of this work; support from the Gordon and Betty Moore Foundation (GBMF9461) for the STM and the theory work; and support from the US DOE under the Basic Energy Sciences programme (grant number DOE/BES DE-FG-02-05ER46200) for the theory and angle-resolved photoemission spectroscopy work. B.L. is supported by the Alfred P. Sloan Foundation, the National Science Foundation through Princeton University’s Materials Research Science and Engineering Center DMR-2011750; and the National Science Foundation under award DMR-2141966. J.-X.Y. acknowledges support from Princeton University, as well as the support from South University of Science and Technology of China principal research grant (number Y01202500). M.Z.H. also acknowledges visiting scientist support from Stanford University during the last phase of this work.

Author information

Authors and Affiliations

Authors

Contributions

All authors discussed the content of the manuscript, and reviewed and edited the entire manuscript.

Corresponding authors

Correspondence to Jia-Xin Yin, Biao Lian or M. Zahid Hasan.

Ethics declarations

Competing interests

The authors declare no competing interests.

Peer review

Peer review information

Nature thanks Domenico Di Sante, Madhav Ghimire and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Additional information

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Yin, JX., Lian, B. & Hasan, M.Z. Topological kagome magnets and superconductors. Nature 612, 647–657 (2022). https://doi.org/10.1038/s41586-022-05516-0

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/s41586-022-05516-0

This article is cited by

Comments

By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing