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  • Letter
  • Open Access

Electronic correlations and topology in Kondo insulator PuB6

K. Gofryk1,2,*, S. Zhou2, N. Poudel3, N. Dice3, D. Murray3, T. Pavlov3, and C. Marianetti4

  • *Contact author: gofryk@inl.gov
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Phys. Rev. Research 8, L012002 – Published 5 January, 2026

DOI: https://doi.org/10.1103/hwpn-gll9

Abstract

Utilizing a combination of dynamical mean field theory (DMFT) and density functional theory, it has been theoretically proposed that PuB6 is a strongly correlated topological insulator characterized by nontrivial Z2 topological invariants and metallic surface states [X. Deng et al., Phys. Rev. Lett. 111, 176404 (2013)]. Here, we demonstrate through low-temperature magnetotransport measurements and first-principles calculations that PuB6 exhibits characteristics of a topological Kondo insulating state. These features include a transition in electrical resistivity from high-temperature, thermally activated behavior with a narrow gap at the Fermi level (Δρ∼20meV) to a distinctive low-temperature plateau, as well as a surface-to-volume dependence of electrical resistivity at low temperatures. The topological nature of PuB6 is further supported by the theoretical calculations, which show that GGA+U is capable of capturing electronic, topological, and lattice properties of PuB6 with much lower computational cost than DMFT.

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References (74)

  1. M. Z. Hasan and C. L. Kane, Colloquium: Topological insulators, Rev. Mod. Phys. 82, 3045 (2010).
  2. N. P. Armitage, E. J. Mele, and A. Vishwanath, Weyl and Dirac semimetals in three-dimensional solids, Rev. Mod. Phys. 90, 015001 (2018).
  3. X. Zhang, et al., Actinide topological insulator materials with strong interaction, Science 335, 1464 (2012).
  4. C. Broyles, et al., High-temperature surface state in Kondo insulator U3Bi4Ni3, Sci. Adv. 11, eadq9952 (2025).
  5. T. Asaba, et al., Colossal anomalous Nernst effect in a correlated noncentrosymmetric kagome ferromagnet, Sci. Adv. 7, eabf1467 (2021).
  6. L. Jiao, et al., Chiral superconductivity in heavy-fermion metal UTe2, Nature (London) 579, 523 (2020).
  7. T. Shishidou, et al., Topological band and superconductivity in UTe2, Phys. Rev. B 103, 104504 (2021).
  8. C. Broyles, et al., UOTe kondo-interacting topological antiferromagnet in a Van der Waals lattice, Adv. Mater. 37, 2414966 (2025).
  9. H. Choi, et al., Experimental and theoretical study of topology and electronic correlations in PuB4, Phys. Rev. B 97, 201114(R) (2018).
  10. D.-C. Ryu, et al., Wallpaper Dirac fermion in a nonsymmorphic topological kondo insulator PuB4, J. Am. Chem. Soc. 142, 19278 (2020).
  11. A. Menth, E. Buehler, and T. H. Geballe, Magnetic and semiconducting properties of SmB6, Phys. Rev. Lett. 22, 295 (1969).
  12. Z. Fisk et al., Kondo insulators, Physica B 206, 798 (1995).
  13. H. Tsunetsugu, M. Sigrist, and K. Ueda, The ground-state phase diagram of the one-dimensional Kondo lattice model, Rev. Mod. Phys. 69, 809 (1997).
  14. P. Riseborough, Heavy fermion semiconductors, Adv. Phys. 49, 257 (2000).
  15. M. Dzero, K. Sun, V. Galitski, and P. Coleman, Topological kondo insulators, Phys. Rev. Lett. 104, 106408 (2010).
  16. M. Dzero, J. Xia, V. Galitski, and P. Coleman, Topological kondo insulators, Annu. Rev. Condens. Matter Phys. 7, 249 (2016).
  17. M. Dzero, K. Sun, P. Coleman, and V. Galitski, Theory of topological Kondo insulators, Phys. Rev. B 85, 045130 (2012).
  18. F. Lu, J. Zhao, H. Weng, Z. Fang, and X. Dai, Correlated topological insulators with mixed valence, Phys. Rev. Lett. 110, 096401 (2013).
  19. V. Alexandrov, M. Dzero, and P. Coleman, Cubic topological kondo insulators, Phys. Rev. Lett. 111, 226403 (2013).
  20. H. Miyazaki, T. Hajiri, T. Ito, S. Kunii, and S.-i. Kimura, Momentum-dependent hybridization gap and dispersive in-gap state of the Kondo semiconductor SmB6, Phys. Rev. B 86, 075105 (2012).
  21. X. Zhang, et al., Hybridization, inter-ion correlation, and surface states in the kondo insulator SmB6, Phys. Rev. X 3, 011011 (2013).
  22. D. J. Kim, et al., Surface Hall effect and nonlocal transport in SmB6 evidence for surface conduction, Sci. Rep. 3, 3150 (2013).
  23. M. Neupane, et al., Surface electronic structure of the topological Kondo-insulator candidate correlated electron system SmB6, Nat. Commun. 4, 2991 (2013).
  24. N. Xu, et al., Surface and bulk electronic structure of the strongly correlated system SmB6 and implications for a topological Kondo insulator, Phys. Rev. B 88, 121102(R) (2013).
  25. J. Jiang, et al., Observation of possible topological in-gap surface states in the Kondo insulator SmB6 by photoemission, Nat. Commun. 4, 3010 (2013).
  26. D. J. Kim, J. Xia, and Z. Fisk, Topological surface state in the Kondo insulator samarium hexaboride, Nat. Mater. 13, 466 (2014).
  27. H. Weng, et al., Topological crystalline kondo insulator in mixed valence ytterbium borides, Phys. Rev. Lett. 112, 016403 (2014).
  28. R. Zhang, et al., Weyl semimetal in the rare-earth hexaboride family supporting a pseudonodal surface and a giant anomalous Hall effect, Phys. Rev. B 105, 165140 (2022).
  29. C.-J. Kang, et al., Electronic structure of YbB6: Is it a topological insulator or not? Phys. Rev. Lett. 116, 116401 (2016).
  30. M. Neupane, et al., Fermi surface topology and hot spot distribution in the Kondo lattice system CeB6, Phys. Rev. B 92, 104420 (2015).
  31. X. Deng, K. Haule, and G. Kotliar, Plutonium hexaboride is a correlated topological insulator, Phys. Rev. Lett. 111, 176404 (2013).
  32. H. A. Eick, Plutonium borides, Inorg. Chem. 4, 1237 (1965).
  33. See Supplemental Material at http://link.aps.org/supplemental/10.1103/hwpn-gll9 for Sec. VI: Synthesis and characterization, which provides a more detailed description of the synthesis process, as well as the preparation and evaluation of the electrical contacts.
  34. N. Poudel, et al., Boundary scattering in topological Kondo insulator SmB6, Appl. Phys. Lett. 126, 192201 (2025).
  35. P. J. W. Moll, et al., High magnetic-field scales and critical currents in SmFeAs(O, F) crystals, Nat. Mater. 9, 628 (2010); Evidence for hydrodynamic electron flow in PdCoO2, Science 351, 1061 (2016); Transport evidence for Fermi-arc-mediated chirality transfer in the Dirac semimetal Cd3As2, Nature (London) 535, 266 (2016).
  36. I. Antonyshyn, et al., Micro-scale device an alternative route for studying the intrinsic properties of solid-state materials the case of semiconducting TaGeIr, Angew. Chem. Int. Ed. 59, 11136 (2020).
  37. S. Hamann, et al., Fermi-surface reconstruction at the metamagnetic high-field transition in uranium mononitride, Phys. Rev. B 104, 155123 (2021).
  38. T. Helm, et al., Field-induced compensation of magnetic exchange as the possible origin of reentrant superconductivity in UTe2, Nat. Commun. 15, 37 (2024).
  39. P. Rogl and P. E. Potter, The B-Pu (boron-plutonium) system, J. Phase Equilib. 18, 467 (1997).
  40. B. J. McDonald and W. I. Stuart, The crystal structure of some plutonium borides, Acta Crystallogr. 13, 447 (1960).
  41. A. B. Shick, L. Havela, A. I. Lichtenstein, and M. I. Katsnelson, Racah materials role of atomic multiplets in intermediate valence systems, Sci. Rep. 5, 15429 (2015).
  42. M. Hosen, et al., Observation of gapped state in rare-earth monopnictide HoSb, Sci. Rep. 10, 12961 (2020).
  43. P. E. Blöchl, Projector augmented-wave method, Phys. Rev. B 50, 17953 (1994).
  44. G. Kresse and D. Joubert, From ultrasoft pseudopotentials to the projector augmented-wave method, Phys. Rev. B 59, 1758 (1999).
  45. G. Kresse and J. Hafner, Ab initio molecular dynamics for liquid metals, Phys. Rev. B 47, 558 (1993).
  46. G. Kresse and J. Furthmuller, Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set, Phys. Rev. B 54, 11169 (1996).
  47. J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized gradient approximation made simple, Phys. Rev. Lett. 77, 3865 (1996).
  48. S. L. Dudarev et al., Electron-energy-loss spectra and the structural stability of nickel oxide An LSDA+U study, Effect of Mott-Hubbard correlations on the electronic structure and structural stability of uranium dioxide, Phys. Rev. B 57, 1505 (1998); Philos. Mag. B 75, 613 (1997).
  49. V. I. Anisimov, J. Zaanen, and O. K. Andersen, Band theory and Mott insulators Hubbard U instead of Stoner I, Phys. Rev. B 44, 943 (1991).
  50. B. Dorado, et al., Advances in first-principles modelling of point defects in UO2 f electron correlations and the issue of local energy minima, J. Phys.: Condens. Matter 25, 333201 (2013).
  51. See Supplemental Material at http://link.aps.org/supplemental/10.1103/hwpn-gll9 for Secs. I and II, which provide a more detailed description of the ground-state search and magnetic ordering in PuB6.
  52. A. B. Shick, et al., Coulomb-U and magnetic-moment collapse in δ-Pu, Europhys. Lett. 69, 588 (2005).
  53. L. V. Pourovskii et al., Dynamical mean-field theory investigation of specific heat and electronic structure of α- and δ-plutonium, Phys. Rev. B 75, 235107 (2007).
  54. W. Ko, et al., Atomic and electronic structure of an alloyed topological insulator, Bi1.5Sb0.5Te1.7Se1.3, Sci. Rep. 3, 2656 (2013).
  55. M. Pickem, E. Maggio, and J. M. Tomczak, Resistivity saturation in Kondo insulators, Commun. Phys. 4, 226 (2021).
  56. P. Syers, D. Kim, M. S. Fuhrer, and J. Paglione, Tuning bulk and surface conduction in the proposed topological kondo insulator SmB6, Phys. Rev. Lett. 114, 096601 (2015).
  57. X. Lei, et al., Surface-induced linear magnetoresistance in the antiferromagnetic topological insulator MnBi2Te4, Phys. Rev. B 102, 235431 (2020).
  58. Y. Shiomi and E. Saitoh, Linear magnetoresistance in a topological insulator Ru2Sn3, AIP Adv. 7, 035011 (2017).
  59. J. Feng, et al., Large linear magnetoresistance in Dirac semimetal Cd3As2 with Fermi surfaces close to the Dirac points, Phys. Rev. B 92, 081306(R) (2015).
  60. M. Novak, et al., Large linear magnetoresistance in the Dirac semimetal TlBiSSe, Phys. Rev. B 91, 041203(R) (2015).
  61. S. K. Kushwaha, et al., Bulk crystal growth and electronic characterization of the 3D Dirac semimetal Na3Bi, APL Mater. 3, 041504 (2015).
  62. S. Thomas, et al., Weak antilocalization and linear magnetoresistance in the surface state of SmB6, Phys. Rev. B 94, 205114 (2016).
  63. S. Singh, et al., Linear magnetoresistance and surface to bulk coupling in topological insulator thin films, J. Phys.: Condens. Matter 29, 505601 (2017).
  64. H. Lu and L. Huang, Quasiparticle multiplets and 5f electronic correlation in prototypical plutonium borides, J Phys.: Condens. Matter 34, 215601 (2022).
  65. J. H. Shim, K. Haule, and G. Kotliar, Fluctuating valence in a correlated solid and the anomalous properties of δ-plutonium, Nature (London) 446, 513 (2007).
  66. M.-T. Suzuki and P. M. Oppeneer, Dynamical mean-field theory of a correlated gap formation in plutonium monochalcogenides, Phys. Rev. B 80, 161103(R) (2009).
  67. J.-X. Zhu, et al., Electronic structure and correlation effects in PuCoIn5 as compared to PuCoGa5, Europhys. Lett. 97, 57001 (2012); Nat. Commun. 4, 2644 (2013).
  68. M. Cococcioni and S. de Gironcoli, Linear response approach to the calculation of the effective interaction parameters in the LDA+U method, Phys. Rev. B 71, 035105 (2005).
  69. See Supplemental Material at http://link.aps.org/supplemental/10.1103/hwpn-gll9 for Sects. III–V, which provide a more detailed description on the effect of Hubbard U on the lattice structure and electronic band structure, tight-binding model used, and the linear response approach to determine the Hubbard U.
  70. L. Fu, M. Kornbluth, Z. Cheng, and C. A. Marianetti, Group theoretical approach to computing phonons and their interactions, Phys. Rev. B 100, 014303 (2019).
  71. P. A. Alekseev, et al., Lattice dynamics of intermediate valence semiconductor SmB6, Europhys. Lett. 10, 457 (1989).
  72. M.-E. Boulanger, et al., Field-dependent heat transport in the Kondo insulator SmB6 Phonons scattered by magnetic impurities, Phys. Rev. B 97, 245141 (2018).
  73. J. Knolle and N. R. Cooper, Excitons in topological Kondo insulators theory of thermodynamic and transport anomalies in SmB6, Phys. Rev. Lett. 118, 096604 (2017).
  74. M. E. Valentine, et al., Breakdown of the Kondo insulating state in SmB6 by introducing Sm vacancies, Phys. Rev. B 94, 075102 (2016).

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Phys. Rev. Research 8, L012002– Published 5 January, 2026
  • Received 5 March 2025
  • Accepted 14 November 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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