Observation of Rashba-Surface-Band-Dependent Yu–Shiba–Rusinov States in a Gold-Based Superconductor AuSn<sub>4</sub>
The interplay between the Rashba effect, superconductivity, and magnetism in gold-based superconductors provides a platform for exploring topological superconductivity, yet the interaction between Rashba bands and superconducting bound states remains unexplored. Here, we report Rashba-surface-band-dependent Yu-Shiba-Rusinov (YSR) states around Fe adatoms on the surfaces of AuSn<sub>4</sub>, using ultralow temperature (5 mK) scanning tunneling microscope/spectroscopy. On Au-terminated surfaces with Rashba bands, most Fe atoms occupy Au vacancies, while only a few adsorb on the Sn-terminated surfaces with dominant bulk metallic states. Remarkably, YSR states localized on the Fe atom are observed on Sn-terminated surfaces but absent on Au-terminated surfaces. First-principle calculations reveal a significant magnetic moment for Fe adatoms on Sn surfaces compared to a nearly negligible value on Au surfaces, which elucidates the observed surface-dependent YSR states. The termination-dependence local moment arises from the interplay of Rashba surface bands and <i>s</i>-<i>d</i> coupling, as described by the Anderson <i>s</i>-<i>d</i> exchange model.
Authors
- Hui Nan Guo (ORCID: https://orcid.org/0000-0002-7874-7273)
- Ruisong Ma (ORCID: https://orcid.org/0000-0002-9954-4416)
- Chengmin Shen (ORCID: https://orcid.org/0000-0003-4716-9367)
- Haitao Yang
- Guangyuan Han (ORCID: https://orcid.org/0000-0002-8810-5231)
- Senhao Lv
- Hong‐Jun Gao (ORCID: https://orcid.org/0000-0002-6766-0623)
- Qing Huan (ORCID: https://orcid.org/0000-0003-0872-8955)
- Rui Song (ORCID: https://orcid.org/0000-0002-6965-0621)
- Zichen Huang (ORCID: https://orcid.org/0000-0003-4053-0201)
- Hui Chen (ORCID: https://orcid.org/0000-0002-3369-8113)
- Hao Zhang (ORCID: https://orcid.org/0000-0002-0840-0995)
- Geng Li (ORCID: https://orcid.org/0000-0002-3347-7222)
- Guoyu Xian
Institutions
- Chinese Academy of Sciences (CN)
- Hefei University (CN)
- FZU ‒ Institute of Physics of the Academy of Sciences of the Czech Republic (CZ)
- Yukhnovskii Institute for Condensed Matter Physics of the National Academy of Sciences of Ukraine (UA)
- Science and Technology on Surface Physics and Chemistry Laboratory (CN)
- Institute of Physics (CN)
- National Laboratory for Superconductivity (CN)
- University of Chinese Academy of Sciences (CN)
Publication Details
- Journal
- Nano Letters
- Published
- 2025-03-24
- DOI
- https://doi.org/10.1021/acs.nanolett.5c00523
- Citations
- 2
- Primary Topic
- Iron-based superconductors research
- Type
- article
- Field-Weighted Citation Impact
- 0.85
Funders
- National Natural Science Foundation of China
- Chinese Academy of Sciences
- National Key Research and Development Program of China