Superconductivity and a van Hove singularity confined to the surface of a topological semimetal
The interplay between topology and superconductivity generated great interest in condensed matter physics. Here, we unveil an unconventional two-dimensional superconducting state in the Dirac nodal line semimetal ZrAs<sub>2</sub> which is exclusively confined to the top and bottom surfaces within the crystal's ab plane. As a remarkable consequence, we present the first clear evidence of a Berezinskii-Kosterlitz-Thouless (BKT) transition occurring solely on a material's surface-specifically, ZrAs₂-unlike the inconsistent reports on PtBi₂, CaAgP, and CaAg₁₋ₓPdₓP. Furthermore, we find that these same surfaces also host a two-dimensional van Hove singularity near the Fermi energy. This leads to enhanced electronic correlations that contribute to the stabilization of superconductivity at the surface of ZrAs<sub>2</sub>. The`surface-confined nature of the van Hove singularity and associated superconductivity, realized for the first time, allows exploring the interplay between low-dimensional quantum topology and superconductivity in a bulk material without resorting to the superconducting proximity effect.
Authors
- Fei Xue (ORCID: https://orcid.org/0000-0002-1737-2332)
- Byung‐Hoon Kim (ORCID: https://orcid.org/0000-0001-8949-4833)
- Tyler A. Cochran (ORCID: https://orcid.org/0000-0003-1745-8467)
- Zi‐Jia Cheng (ORCID: https://orcid.org/0000-0002-9473-7753)
- Xiàn Yáng (ORCID: https://orcid.org/0000-0002-5019-374X)
- Mehdi Kargarian (ORCID: https://orcid.org/0000-0003-4242-8219)
- Yu-Xiao Jiang (ORCID: https://orcid.org/0000-0002-7958-3100)
- Hubertus Luetkens (ORCID: https://orcid.org/0000-0002-5842-9788)
- Zahir Muhammad (ORCID: https://orcid.org/0000-0003-2356-5760)
- Rajibul Islam (ORCID: https://orcid.org/0000-0002-6483-8932)
- T. J. Hicken (ORCID: https://orcid.org/0000-0003-4812-0426)
- Weisheng S. Zhao (ORCID: https://orcid.org/0000-0001-8088-0404)
- Brian Casas
- I. E. Perakis (ORCID: https://orcid.org/0000-0002-8882-0067)
- M. Zahid Hasan (ORCID: https://orcid.org/0000-0001-9730-3128)
- Luis Balicas (ORCID: https://orcid.org/0000-0002-5209-0293)
- Md Shafayat Hossain (ORCID: https://orcid.org/0000-0002-3744-5877)
- Maksim Litskevich (ORCID: https://orcid.org/0000-0003-3049-6521)
- Jonas A. Krieger (ORCID: https://orcid.org/0000-0003-3337-5530)
- Qi Zhang (ORCID: https://orcid.org/0000-0002-6261-2606)
- Zurab Guguchia (ORCID: https://orcid.org/0000-0002-5498-328X)
Institutions
- Florida State University (US)
- Zhejiang International Studies University (CN)
- Sharif University of Technology (IR)
- Princeton University (US)
- University of Alabama at Birmingham (US)
- Hefei University (CN)
- Institute for Advanced Study (US)
- Institute of Microelectronics (CN)
- National High Magnetic Field Laboratory (US)
Publication Details
- Journal
- Nature Communications
- Published
- 2025-04-29
- DOI
- https://doi.org/10.1038/s41467-025-58024-w
- Citations
- 3
- Primary Topic
- Topological Materials and Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 3.74
Funders
- National Science Foundation
- U.S. Department of Energy
- Gordon and Betty Moore Foundation
- National High Magnetic Field Laboratory
- Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung
- National Natural Science Foundation of China
- Beihang University
- Sharif University of Technology
- Iran National Science Foundation
- Paul Scherrer Institut
- Division of Materials Research
- High Magnetic Field Laboratory, Chinese Academy of Sciences