Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access

Stabilization of U 5f2 configuration in UTe2 through U 6d dimers in the presence of Te2 chains

Denise S. Christovam1, Martin Sundermann1,2, Andrea Marino1, Daisuke Takegami1,*, Johannes Falke1, Paulius Dolmantas1, Manuel Harder3,4, Hlynur Gretarsson2,5, Bernhard Keimer5 et al.

Andrei Gloskovskii2, Maurits W. Haverkort6, Ilya Elfimov7, Gertrud Zwicknagl1,8, Alexander V. Andreev9, Ladislav Havela10, Mitchell M. Bordelon11, Eric D. Bauer11, Priscila F. S. Rosa11, Andrea Severing1,12, and Liu Hao Tjeng1

  • *Present address: Department of Applied Physics, Waseda University, Shinjuku, Tokyo 169-8555, Japan.

Phys. Rev. Research 6, 033299 – Published 16 September, 2024

DOI: https://doi.org/10.1103/PhysRevResearch.6.033299

Abstract

We investigate the topological superconductor candidate UTe2 using high-resolution valence-band resonant inelastic x-ray scattering at the U M4,5 edges. We observe atomiclike low-energy excitations that support the correlated nature of this unconventional superconductor. These excitations originate from the U 5f2 configuration, which is unexpected since the short Te2-Te2 distances exclude Te2 being 2−. By utilizing the photoionization cross-section dependence of the photoemission spectra in combination with band structure calculations, we infer that the stabilization of the U 5f2 configuration is due to the U 6d bonding states in the U dimers acting as a charge reservoir. Our results emphasize that the description of the physical properties should commence with a 5f2 ansatz.

View figure in article

Physics Subject Headings (PhySH)

Article Text

Supplemental Material

References (71)

  1. S. Ran, C. Eckberg, Q.-P. Ding, Y. Furukawa, T. Metz, S. R. Saha, I.-L. Liu, M. Zic, H. Kim, J. Paglione, and N. P. Butch, Nearly ferromagnetic spin-triplet superconductivity, Science 365, 684 (2019).
  2. D. Aoki, A. Nakamura, F. Honda, D. Li, Y. Homma, Y. Shimizu, Y. J. Sato, G. Knebel, J.-P. Brison, A. Pourret, D. Braithwaite, G. Lapertot, Q. Niu, M. Vališka, H. Harima, and J. Flouquet, Unconventional superconductivity in heavy fermion UTe2, J. Phys. Soc. Jpn. 88, 043702 (2019).
  3. A. de Visser, UTe2: A new spin-triplet pairing superconductor, JPSJ News and Comments 16, 08 (2019).
  4. S. K. Lewin, C. E. Frank, S. Ran, J. Paglione, and N. P. Butch, A review of UTe2 at high magnetic fields, Rep. Prog. Phys. 86, 114501 (2023).
  5. I. M. Hayes, D. S. Wei, T. Metz, J. Zhang, Y. S. Eo, S. Ran, S. R. Saha, J. Collini, N. P. Butch, D. F. Agterberg, A. Kapitulnik, and J. Paglione, Multicomponent superconducting order parameter in UTe2, Science 373, 797 (2021).
  6. J. Ishizuka and Y. Yanase, Periodic Anderson model for magnetism and superconductivity in UTe2, Phys. Rev. B 103, 094504 (2021).
  7. K. Ishihara, M. Roppongi, M. Kobayashi, K. Imamura, Y. Mizukami, H. Sakai, P. Opletal, Y. Tokiwa, Y. Haga, K. Hashimoto, and T. Shibauchi, Chiral superconductivity in UTe2 probed by anisotropic low-energy excitations, Nat. Commun. 14, 2966 (2023).
  8. P. F. S. Rosa, A. Weiland, S. S. Fender, B. L. Scott, F. Ronning, J. D. Thompson, E. D. Bauer, and S. M. Thomas, Single thermodynamic transition at 2 K in superconducting UTe2, Commun. Mater. 3, 33 (2022).
  9. S. Suetsugu, M. Shimomura, M. Kamimura, T. Asaba, H. Asaeda, Y. Kosuge, Y. Sekino, S. Ikemori, Y. Kasahara, Y. Kohsaka, M. Lee, Y. Yanase, H. Sakai, P. Opletal, Y. Tokiwa, Y. Haga, and Y. Matsuda, Fully gapped pairing state in spin-triplet superconductor UTe2 Sci. Adv. 10, eadk3772 (2024).
  10. F. Theuss, A. Shragai, G. Grissonnanche, I. M. Hayes, S. R. Saha, Y. S. Eo, A. Suarez, T. Shishidou, N. P. Butch, J. Paglione, and B. J. Ramshaw, Single-component superconductivity in UTe2 at ambient pressure, Nat. Phys. 20, 1124, (2024) .
  11. S. Lee, A. J. Woods, P. F. S. Rosa, S. M. Thomas, E. D. Bauer, S.-Z. Lin, and R. Movshovich, Anisotropic field-induced changes in the superconducting order parameter of UTe2, arXiv:2310.04938.
  12. S.-i. Fujimori, I. Kawasaki, Y. Takeda, H. Yamagami, A. Nakamura, Y. Homma, and D. Aoki, Electronic structure of UTe2 studied by photoelectron spectroscopy, J. Phys. Soc. Jpn. 88, 103701 (2019).
  13. L. Miao, S. Liu, Y. Xu, E. C. Kotta, C.-J. Kang, S. Ran, J. Paglione, G. Kotliar, N. P. Butch, J. D. Denlinger, and L. A. Wray, Low energy band structure and symmetries of UTe2 from angle-resolved photoemission spectroscopy, Phys. Rev. Lett. 124, 076401 (2020).
  14. S. M. Thomas, F. B. Santos, M. H. Christensen, T. Asaba, F. Ronning, J. D. Thompson, E. D. Bauer, R. M. Fernandes, G. Fabbris, and P. F. S. Rosa, Evidence for a pressure-induced antiferromagnetic quantum critical point in intermediate-valence UTe2, Sci. Adv. 6, eabc8709 (2020).
  15. S.-i. Fujimori, I. Kawasaki, Y. Takeda, H. Yamagami, A. Nakamura, Y. Homma, and D. Aoki, Core-level photoelectron spectroscopy study of UTe2, J. Phys. Soc. Jpn. 90, 015002 (2021).
  16. A. B. Shick, S.-I. Fujimori, and W. E. Pickett, UTe2: A nearly insulating half-filled j=525f3 heavy-fermion metal, Phys. Rev. B 103, 125136 (2021).
  17. D. Aoki, H. Sakai, P. Opletal, Y. Tokiwa, J. Ishizuka, Y. Yanase, H. Harima, A. Nakamura, D. Li, Y. Homma, Y. Shimizu, G. Knebel, J. Flouquet, and Y. Haga, First observation of the de Haas–van Alphen effect and Fermi surfaces in the unconventional superconductor UTe2, J. Phys. Soc. Jpn. 91, 083704 (2022) .
  18. S. Liu, Y. Xu, E. C. Kotta, L. Miao, S. Ran, J. Paglione, N. P. Butch, J. D. Denlinger, Y.-D. Chuang, and L. A. Wray, Identifying f-electron symmetries of UTe2 with O-edge resonant inelastic x-ray scattering, Phys. Rev. B 106, L241111 (2022).
  19. F. Wilhelm, J.-P. Sanchez, D. Braithwaite, G. Knebel, G. Lapertot, and A. Rogalev, Investigating the electronic states of UTe2 using x-ray spectroscopy, Commun. Phys. 6, 96 (2023).
  20. T. Shishidou, H. G. Suh, P. M. R. Brydon, M. Weinert, and D. F. Agterberg, Topological band and superconductivity in UTe2, Phys. Rev. B 103, 104504 (2021).
  21. T. Hazra and P. Coleman, Triplet pairing mechanisms from Hund's-Kondo models: Applications to UTe2 and CeRh2As2, Phys. Rev. Lett. 130, 136002 (2023).
  22. S. Khmelevskyi, L. V. Pourovskii, and E. A. Tereshina-Chitrova, Structure of the normal state and origin of the Schottky anomaly in the correlated heavy-fermion superconductor Ute2, Phys. Rev. B 107, 214501 (2023).
  23. V. Hutanu, H. Deng, S. Ran, W. T. Fuhrman, H. Thoma, and N. P. Butch, Low-temperature crystal structure of the unconventional spin-triplet superconductor UTe2 from single-crystal neutron diffraction, Acta Crystallogr. Sect. B 76, 137 (2020).
  24. H. Sakai, P. Opletal, Y. Tokiwa, E. Yamamoto, Y. Tokunaga, S. Kambe, and Y. Haga, Single crystal growth of superconducting UTe2 by molten salt flux method, Phys. Rev. Mater. 6, 073401 (2022).
  25. Z. Wu, T. I. Weinberger, J. Chen, A. Cabala, D. V. Chichinadze, D. Shaffer, J. Pospíšil, J. Prokleška, T. Haidamak, G. Bastien, V. Sechovský, A. J. Hickey, M. J. Mancera-Ugarte, S. Benjamin, D. E. Graf, Y. Skourski, G. G. Lonzarich, M. Vališka, F. M. Grosche, and A. G. Eaton, Enhanced triplet superconductivity in next-generation ultraclean UTe2, Proc. Nat. Acad. Sci. USA 121, e2403067121 (2024).
  26. H. Matsumura, H. Fujibayashi, K. Kinjo, S. Kitagawa, K. Ishida, Y. Tokunaga, H. Sakai, S. Kambe, A. Nakamura, Y. Shimizu, Y. Homma, D. Li, F. Honda, and D. Aoki, Large reduction in the a-axis knight shift on UTe2 with Tc = 2.1 k, J. Phys. Soc. Jpn. 92, 063701 (2023).
  27. G. Knebel, W. Knafo, A. Pourret, Q. Niu, M. Vališka, D. Braithwaite, G. Lapertot, M. Nardone, A. Zitouni, S. Mishra, I. Sheikin, G. Seyfarth, J.-P. Brison, D. Aoki, and J. Flouquet, Field-reentrant superconductivity close to a metamagnetic transition in the heavy-fermion superconductor UTe2, J. Phys. Soc. Jpn. 88, 063707 (2019).
  28. S. Ran, I.-L. Liu, Y. S. Eo, D. J. Campbell, P. M. Neves, W. T. Fuhrman, S. R. Saha, C. Eckberg, H. Kim, D. Graf, F. Balakirev, J. Singleton, J. Paglione, and N. P. Butch, Extreme magnetic field-boosted superconductivity, Nat. Phys. 15, 1250 (2019).
  29. W. Knafo, T. Thebault, P. Manuel, D. D. Khalyavin, F. Orlandi, E. Ressouche, K. Beauvois, G. Lapertot, K. Kaneko, D. Aoki, D. Braithwaite, G. Knebel, and S. Raymond, Incommensurate antiferromagnetism in UTe2 under pressure, arXiv:2311.05455.
  30. S. Ran, H. Kim, I.-L. Liu, S. R. Saha, I. Hayes, T. Metz, Y. S. Eo, J. Paglione, and N. P. Butch, Enhancement and reentrance of spin triplet superconductivity in UTe2 under pressure, Phys. Rev. B 101, 140503 (2020).
  31. L. Q. Huston, D. Y. Popov, A. Weiland, M. M. Bordelon, P. F. S. Rosa, R. L. Rowland, B. L. Scott, G. Shen, C. Park, E. K. Moss, S. M. Thomas, J. D. Thompson, B. T. Sturtevant, and E. D. Bauer, Metastable phase of UTe2 formed under high pressure above 5 GPa, Phys. Rev. Mater. 6, 114801 (2022).
  32. F. Honda, S. Kobayashi, N. Kawamura, S. I. Kawaguchi, T. Koizumi, Y. J. Sato, Y. Homma, N. Ishimatsu, J. Gouchi, Y. Uwatoko, H. Harima, J. Flouquet, and D. Aoki, Pressure-induced structural phase transition and new superconducting phase in UTe2, J. Phys. Soc. Jpn. 92, 044702 (2023).
  33. H.-H. Kung, R. E. Baumbach, E. D. Bauer, V. K. Thorsmølle, W.-L. Zhang, K. Haule, J. A. Mydosh, and G. Blumberg, Chirality density wave of the hidden order phase in URu2Si2, Science 347, 1339 (2015).
  34. A. Marino, D. S. Christovam, D. Takegami, J. Falke, M. M. F. Carvalho, T. Okauchi, C.-F. Chang, S. G. Altendorf, A. Amorese, M. Sundermann, A. Gloskovskii, H. Gretarsson, B. Keimer, A. V. Andreev, L. Havela, A. Leithe-Jasper, A. Severing, J. Kuneš, L. H. Tjeng, and A. Hariki, Quantifying the U 5f covalence and degree of localization in U intermetallics, Phys. Rev. Res. 6, 033068 (2024).
  35. J. R. Jeffries, K. T. Moore, N. P. Butch, and M. B. Maple, Degree of 5f electron localization in URu2Si2: Electron energy-loss spectroscopy and spin-orbit sum rule analysis, Phys. Rev. B 82, 033103 (2010).
  36. S.-i. Fujimori, T. Ohkochi, I. Kawasaki, A. Yasui, Y. Takeda, T. Okane, Y. Saitoh, A. Fujimori, H. Yamagami, Y. Haga, E. Yamamoto, Y. Tokiwa, S. Ikeda, T. Sugai, H. Ohkuni, N. Kimura, and Y. Onuki, Electronic structure of heavy fermion uranium compounds studied by core-level photoelectron spectroscopy, J. Phys. Soc. Jpn. 81, 014703 (2012).
  37. L. A. Wray, J. Denlinger, S. W. Huang, H. He, N. P. Butch, M. B. Maple, Z. Hussain, and Y. D. Chuang, Spectroscopic determination of the atomic f-electron symmetry underlying hidden order in URu2Si2, Phys. Rev. Lett. 114, 236401 (2015).
  38. C. H. Booth, S. A. Medling, J. G. Tobin, R. E. Baumbach, E. D. Bauer, D. Sokaras, D. Nordlund, and T.-C. Weng, Probing 5f-state configurations in URu2Si2 with U LIII-edge resonant x-ray emission spectroscopy, Phys. Rev. B 94, 045121 (2016).
  39. M. Sundermann, M. W. Haverkort, S. Agrestini, A. Al-Zein, M. Moretti Sala, Y. Huang, M. Golden, A. de Visser, P. Thalmeier, L. H. Tjeng, and A. Severing, Direct bulk-sensitive probe of 5f symmetry in URu2Si2, Proc. Nat. Acad. Sci. USA 113, 13989 (2016).
  40. K. O. Kvashnina, H. C. Walker, N. Magnani, G. H. Lander, and R. Caciuffo, Resonant x-ray spectroscopy of uranium intermetallics at the M4,5 edges of uranium, Phys. Rev. B 95, 245103 (2017).
  41. F. Wilhelm, J. P. Sanchez, and A. Rogalev, Magnetism of uranium compounds probed by XMCD spectroscopy, J. Phys. D: Appl. Phys. 51, 333001 (2018).
  42. G. van der Laan and B. T. Thole, X-ray-absorption sum rules in jj-coupled operators and ground-state moments of actinide ions, Phys. Rev. B 53, 14458 (1996).
  43. G. van der Laan, K. T. Moore, J. G. Tobin, B. W. Chung, M. A. Wall, and A. J. Schwartz, Applicability of the spin-orbit sum rule for the actinide 5f states, Phys. Rev. Lett. 93, 097401 (2004).
  44. G. van der Laan, private communication (2024).
  45. E. L. Bright, L. Xu, L. M. Harding, R. Springell, A. C. Walters, M. Sundermann, M. Garcia-Fernandez, S. Agrestini, R. Caciuffo, G. van der Laan, and G. H. Lander, Resonant inelastic x-ray scattering from U3O8 and UN, J. Phys.: Cond. Mat. 35, 175501 (2023).
  46. A. Marino, M. Sundermann, D. S. Christovam, A. Amorese, C.-F. Chang, P. Dolmantas, A. H. Said, H. Gretarsson, B. Keimer, M. W. Haverkort, A. V. Andreev, L. Havela, P. Thalmeier, L. H. Tjeng, and A. Severing, Singlet magnetism in intermetallic UGa2 unveiled by inelastic x-ray scattering, Phys. Rev. B 108, 045142 (2023).
  47. D. Ketenoglu, M. Harder, K. Klementiev, M. Upton, M. Taherkhani, M. Spiwek, F.-U. Dill, H.-C. Wille, and H. Yavaş, Resonant inelastic X-ray scattering spectrometer with 25meV resolution at the Cu K-edge, J. Synchrotron Rad. 22, 961 (2015).
  48. A. H. Said, T. Gog, M. Wieczorek, X. Huang, D. Casa, E. Kasman, R. Divan, and J. H. Kim, High-energy-resolution diced spherical quartz analyzers for resonant inelastic X-ray scattering, J. Synchrotron Radiat. 25, 373 (2018).
  49. H. Gretarsson, D. Ketenoglu, M. Harder, S. Mayer, F.-U. Dill, M. Spiwek, H. Schulte-Schrepping, M. Tischer, H.-C. Wille, B. Keimer, and H. Yavaş, IRIXS: a resonant inelastic x-ray scattering instrument dedicated to X-rays in the intermediate energy range, J. Synchrotron Rad. 27, 538 (2020).
  50. See Supplemental Material at http://link.aps.org/supplemental/10.1103/PhysRevResearch.6.033299 for further information on sample preparation & quality, experimental set-ups, simulations, band structure calculations, and cross-section analysis.
  51. A. Lawson, A. Williams, J. Smith, P. Seeger, J. Goldstone, J. O'Rourke, and Z. Fisk, Magnetic neutron diffraction study of UGa3 and UGa2, J. Magn. Magn. Mater. 50, 83 (1985).
  52. E. Yamamoto, Y. Hirose, K. Enoki, K. Mitamura, K. Sugiyama, T. Takeuchi, M. Hagiwara, K. Kindo, Y. Haga, R. Settai, and Y. Onuki, Heavy fermion state in antiferromagnet UCd11, J. Phys. Soc. Jpn. 81, SB023 (2012).
  53. A. Amorese, M. Sundermann, B. Leedahl, A. Marino, D. Takegami, H. Gretarsson, A. Gloskovskii, C. Schlueter, M. W. Haverkort, Y. Huang, M. Szlawska, D. Kaczorowski, S. Ran, M. B. Maple, E. D. Bauer, A. Leithe-Jasper, P. Hansmann, P. Thalmeier, L. H. Tjeng, and A. Severing, From antiferromagnetic and hidden order to Pauli paramagnetism in UM2Si2 compounds with 5f electron duality, Proc. Natl. Acad. Sci. USA 117, 30220 (2020).
  54. M. W. Haverkort, Quanty for core level spectroscopy - excitons, resonances and band excitations in time and frequency domain, J. Phys.: Conf. Ser. 712, 012001 (2016).
  55. R. D. Cowan, The Theory of Atomic Structure and Spectra (University of California Press, Berkeley and Los Angeles, 1981).
  56. A. Tanaka and T. Jo, Resonant 3d, 3p and 3s photoemission in transition metal oxides predicted at 2p threshold, J. Phys. Soc. Jpn. 63, 2788 (1994).
  57. F. de Groot and A. Kotani, Core Level Spectrocopy of Solis, Advances in Condensed Matter Science (CRC Press, Boca Raton, 2008), Vol. 6.
  58. S. Agrestini, C.-Y. Kuo, M. Moretti Sala, Z. Hu, D. Kasinathan, K.-T. Ko, P. Glatzel, M. Rossi, J.-D. Cafun, K. O. Kvashnina, A. Matsumoto, T. Takayama, H. Takagi, L. H. Tjeng, and M. W. Haverkort, Long-range interactions in the effective low-energy hamiltonian of Sr2IrO4: A core-to-core resonant inelastic x-ray scattering study, Phys. Rev. B 95, 205123 (2017).
  59. V. Jović, Tellurium, Geochemistry, Encyclopedia of Earth Science (EESS) (Springer, Dordrecht, Netherlands, 1998), pp. 621–622.
  60. M. Lafrentz, D. Brunne, B. Kaminski, V. V. Pavlov, A. B. Henriques, R. V. Pisarev, D. R. Yakovlev, G. Springholz, G. Bauer, E. Abramof, P. H. O. Rappl, and M. Bayer, Optical third-harmonic spectroscopy of the magnetic semiconductor EuTe, Phys. Rev. B 82, 235206 (2010).
  61. K. Stöwe, Uncommon valence states in the metallic lanthanide and actinide diiodides MI2 (M=La, Ce, Nd, Gd and Th) and in the uranium tellurides UTe2, U2Te5 and UTe3 Part 2: the uranium tellurides UTe2, U2Te5 and α−UTe3, J. Alloys Compd. 246, 111 (1997).
  62. K. Koepernik and H. Eschrig, Full-potential nonorthogonal local-orbital minimum-basis band-structure scheme, Phys. Rev. B 59, 1743 (1999).
  63. J. P. Perdew and Y. Wang, Accurate and simple analytic representation of the electron-gas correlation energy, Phys. Rev. B 45, 13244 (1992).
  64. M. B. Trzhaskovskaya, V. I. Needov, and V. G. Yarzhemsky, Photoelectron angular distribution parameters for elements Z = 1 to Z = 54 in the photoelectron energy range 100–5000 eV, At. Data Nucl. Data Tables 77, 97 (2001).
  65. M. B. Trzhaskovskaya, V. I. Needov, and V. G. Yarzhemsky, Photoelectron angular distribution parameters for elements Z = 55 to Z = 100 in the photoelectron energy range 100–5000 eV, At. Data Nucl. Data Tables 82, 257 (2002).
  66. M. B. Trzhaskovskaya, V. K. Nikulin, V. I. Nefedov, and V. G. Yarzhemsky, Non-dipole second order parameters of the photoelectron angular distribution for elements Z = 1–100 in the photoelectron energy range 1–10 keV, At. Data Nucl. Data Tables 92, 245 (2006).
  67. H. Rosner, J. Gegner, D. Regesch, W. Schnelle, R. Gumeniuk, A. Leithe-Jasper, H. Fujiwara, T. Haupricht, T. C. Koethe, H.-H. Hsieh, H.-J. Lin, C. T. Chen, A. Ormeci, Y. Grin, and L. H. Tjeng, Electronic structure of SrPt4Ge12: Combined photoelectron spectroscopy and band structure study, Phys. Rev. B 80, 075114 (2009).
  68. D. Takegami, L. Nicolaï, T. C. Koethe, D. Kasinathan, C. Y. Kuo, Y. F. Liao, K. D. Tsuei, G. Panaccione, F. Offi, G. Monaco, N. B. Brookes, J. Minár, and L. H. Tjeng, Valence band hard x-ray photoelectron spectroscopy on 3d transition-metal oxides containing rare-earth elements, Phys. Rev. B 99, 165101 (2019).
  69. D. Takegami, C.-Y. Kuo, K. Kasebayashi, J.-G. Kim, C. F. Chang, C. E. Liu, C. N. Wu, D. Kasinathan, S. G. Altendorf, K. Hoefer, F. Meneghin, A. Marino, Y. F. Liao, K. D. Tsuei, C. T. Chen, K.-T. Ko, A. Günther, S. G. Ebbinghaus, J. W. Seo, D. H. Lee et al., CaCu3Ru4O12: A high-Kondo-temperature transition-metal oxide, Phys. Rev. X 12, 011017 (2022).
  70. S. G. Altendorf, D. Takegami, A. Meléndez-Sans, C. F. Chang, M. Yoshimura, K. D. Tsuei, A. Tanaka, M. Schmidt, and L. H. Tjeng, Electronic structure of the Fe2+ compound FeWO4: A combined experimental and theoretical x-ray photoelectron spectroscopy study, Phys. Rev. B 108, 085119 (2023).
  71. C. Schlueter, A. Gloskovskii, K. Ederer, I. Schostak, S. Piec, I. Sarkar, Y. Matveyev, P. Lömker, M. Sing, R. Claessen, C. Wiemann, C. M. Schneider, K. Medjanik, G. Schönhense, P. Amann, A. Nilsson, and W. Drube, The new dedicated HAXPES beamline P22 at PETRA III, AIP Conf. Proc. 2054, 040010 (2019).

Outline

Information

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation