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Modulation of superconducting properties by the charge density wave at the surface of 2H−NbSe2

T. Hanaguri*

  • *Contact author: hanaguri@riken.jp
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Phys. Rev. Research 8, 013164 – Published 12 February, 2026

DOI: https://doi.org/10.1103/jgtl-v58d

Abstract

To investigate the interplay between charge density wave (CDW) and superconductivity, we performed ultralow-temperature spectroscopic-imaging scanning tunneling microscopy on the cleaved surface of the layered superconductor 2H−NbSe2. We found that the superconducting-gap spectrum exhibits intricate structures reflecting the anisotropic gaps opening on multiple Fermi surfaces. Notably, none of the characteristic energy scales apparent in the spectral gap show appreciable spatial variations, suggesting that the finite-momentum pairing is negligible. Instead, the spectral weight near the coherence peak is modulated with the same periodicity as the CDW. The maximum position of the coherence-peak-weight modulation coincides with neither the peak nor the bottom of the CDW modulation; rather, it aligns with the center of one of the two inequivalent triangular plaquettes that comprise the CDW unit cell. This distribution pattern of Bogoliubov quasiparticles directly results from the broken in-plane inversion symmetry at the surface of 2H−NbSe2, which may activate Ising spin-orbit coupling.

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References (28)

  1. P. Fulde and R. A. Ferrell, Superconductivity in a strong spin-exchange field, Phys. Rev. 135, A550 (1964).
  2. A. Larkin and Y. Ovchinnikov, Inhomogeneous state of superconductors, Sov. Phys. JETP 20, 762 (1965).
  3. Y. Matsuda and H. Shimahara, Fulde-Ferrell-Larkin-Ovchinnikov state in heavy fermion superconductors, J. Phys. Soc. Jpn. 76, 051005 (2007).
  4. D. F. Agterberg, J. C. S. Davis, S. D. Edkins, E. Fradkin, D. J. Van Harlingen, S. A. Kivelson, P. A. Lee, L. Radzihovsky, J. M. Tranquada, and Y. Wang, The physics of pair-density waves: Cuprate superconductors and beyond, Annu. Rev. Condens. Matter Phys. 11, 231 (2020).
  5. K. Machida, T. Kōyama, and T. Matsubara, Theory of charge-density-wave superconductors, Phys. Rev. B 23, 99 (1981).
  6. S. Manzeli, D. Ovchinnikov, D. Pasquier, O. V. Yazyev, and A. Kis, 2D transition metal dichalcogenides, Nat. Rev. Mater. 2, 17033 (2017).
  7. S.-i. Uchida, Ubiquitous charge order correlations in high-temperature superconducting cuprates, J. Phys. Soc. Jpn. 90, 111001 (2021).
  8. B. R. Ortiz, S. M. L. Teicher, Y. Hu, J. L. Zuo, P. M. Sarte, E. C. Schueller, A. M. M. Abeykoon, M. J. Krogstad, S. Rosenkranz, R. Osborn, R. Seshadri, L. Balents, J. He, and S. D. Wilson, Cs3V3Sb5: A Z2 topological kagome metal with a superconducting ground state, Phys. Rev. Lett. 125, 247002 (2020).
  9. T. Kiss, T. Yokoya, A. Chainani, S. Shin, T. Hanaguri, M. Nohara, and H. Takagi, Charge-order-maximized momentum-dependent superconductivity, Nat. Phys. 3, 720 (2007).
  10. D. J. Rahn, S. Hellmann, M. Kalläne, C. Sohrt, T. K. Kim, L. Kipp, and K. Rossnagel, Gaps and kinks in the electronic structure of the superconductor 2H−NbSe2 from angle-resolved photoemission at 1 K, Phys. Rev. B 85, 224532 (2012).
  11. A. Soumyanarayanan, M. M. Yee, Y. He, J. van Wezel, D. J. Rahn, K. Rossnagel, E. W. Hudson, M. R. Norman, and J. E. Hoffman, Quantum phase transition from triangular to stripe charge order in NbSe2, Proc. Natl. Acad. Sci. USA 110, 1623 (2013).
  12. C. J. Arguello, S. P. Chockalingam, E. P. Rosenthal, L. Zhao, C. Gutiérrez, J. H. Kang, W. C. Chung, R. M. Fernandes, S. Jia, A. J. Millis, R. J. Cava, and A. N. Pasupathy, Visualizing the charge density wave transition in 2H−NbSe2 in real space, Phys. Rev. B 89, 235115 (2014).
  13. A. Pásztor, A. Scarfato, M. Spera, F. Flicker, C. Barreteau, E. Giannini, J. v. Wezel, and C. Renner, Multiband charge density wave exposed in a transition metal dichalcogenide, Nat. Commun. 12, 6037 (2021).
  14. A. K. Kundu, A. Rajapitamahuni, E. Vescovo, I. I. Klimovskikh, H. Berger, and T. Valla, Charge density waves and the effects of uniaxial strain on the electronic structure of 2H−NbSe2, Commun. Mater. 5, 208 (2024).
  15. X. Liu, Y. X. Chong, R. Sharma, and J. C. S. Davis, Discovery of a Cooper-pair density wave state in a transition-metal dichalcogenide, Science 372, 1447 (2021).
  16. L. Cao, Y. Xue, Y. Wang, F.-C. Zhang, J. Kang, H.-J. Gao, J. Mao, and Y. Jiang, Directly visualizing nematic superconductivity driven by the pair density wave in NbSe2, Nat. Commun. 15, 7234 (2024).
  17. I. Guillamon, H. Suderow, F. Guinea, and S. Vieira, Intrinsic atomic-scale modulations of the superconducting gap of 2H−NbSe2, Phys. Rev. B 77, 134505 (2008).
  18. T. Dvir, F. Massee, L. Attias, M. Khodas, M. Aprili, C. H. L. Quay, and H. Steinberg, Spectroscopy of bulk and few-layer superconducting NbSe2 with van der Waals tunnel junctions, Nat. Commun. 9, 598 (2018).
  19. A. Sanna, C. Pellegrini, E. Liebhaber, K. Rossnagel, K. J. Franke, and E. K. U. Gross, Real-space anisotropy of the superconducting gap in the charge-density wave material 2H−NbSe2, npj Quantum Mater. 7, 6 (2022).
  20. G. Gye, E. Oh, and H. W. Yeom, Topological landscape of competing charge density waves in 2H−NbSe2, Phys. Rev. Lett. 122, 016403 (2019).
  21. S. Yoshizawa, K. Sagisaka, and H. Sakata, Visualization of alternating triangular domains of charge density waves in 2H−NbSe2 by scanning tunneling microscopy, Phys. Rev. Lett. 132, 056401 (2024).
  22. K. Momma and F. Izumi, VESTA3 for three-dimensional visualization of crystal, volumetric and morphology data, J. Appl. Crystallogr. 44, 1272 (2011).
  23. T. Machida, Y. Kohsaka, and T. Hanaguri, A scanning tunneling microscope for spectroscopic imaging below 90 mK in magnetic fields up to 17.5 T, Rev. Sci. Instrum. 89, 093707 (2018).
  24. K. Maki, Pauli paramagnetism and superconducting state. II, Prog. Theor. Phys. 32, 29 (1964).
  25. Y. Kohsaka, SIDAM, https://github.com/yuksk/SIDAM (2021).
  26. Y. Kohsaka, C. Taylor, K. Fujita, A. Schmidt, C. Lupien, T. Hanaguri, M. Azuma, M. Takano, H. Eisaki, H. Takagi, S. Uchida, and J. C. Davis, An intrinsic bond-centered electronic glass with unidirectional domains in underdoped cuprates, Science 315, 1380 (2007).
  27. L. Kong, M. Papaj, H. Kim, Y. Zhang, E. Baum, H. Li, K. Watanabe, T. Taniguchi, G. Gu, P. A. Lee, and S. Nadj-Perge, Cooper-pair density modulation state in an iron-based superconductor, Nature (London) 640, 55 (2025).
  28. X. Xi, Z. Wang, W. Zhao, J.-H. Park, K. T. Law, H. Berger, L. Forró, J. Shan, and K. F. Mak, Ising pairing in superconducting NbSe2 atomic layers, Nat. Phys. 12, 139 (2016).

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Phys. Rev. Research 8, 013164– Published 12 February, 2026
  • Received 30 September 2025
  • Accepted 21 January 2026
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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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