Revealing the Microscopic Mechanism of Elementary Vortex Pinning in Superconductors
Vortex pinning is a crucial factor that determines the critical current of practical superconductors and enables their diverse applications. However, the underlying mechanism of vortex pinning has long been elusive, lacking a clear microscopic explanation. Here, using high-resolution scanning tunneling microscopy, we studied single vortex pinning induced by point defect in layered FeSe-based superconductors. We found the defect-vortex interaction drives low-energy vortex bound states away from <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mi>E</a:mi><a:mi mathvariant="normal">F</a:mi></a:msub></a:mrow></a:math>, creating a “mini” gap that effectively lowers the system energy and enhances pinning. By measuring the local density of states, we directly obtained the elementary pinning energy and estimated the pinning force via the spatial gradient of pinning energy. The results are consistent with bulk critical current measurement. Furthermore, we showed that a general microscopic quantum model incorporating defect-vortex interaction can naturally capture our observation. It suggests that the local pairing near pinned vortex core is actually enhanced compared to unpinned vortex, which is beyond the traditional understanding that nonsuperconducting regions pin vortices. Our study thus unveils a general microscopic mechanism of vortex pinning in superconductors and provides insights for enhancing the critical current of practical superconductors. Published by the American Physical Society 2024
Authors
- Chen Chen (ORCID: https://orcid.org/0000-0003-4130-9883)
- Xinqiang Wang (ORCID: https://orcid.org/0000-0001-5514-8588)
- D. L. Feng (ORCID: https://orcid.org/0000-0002-1687-0970)
- Cuixiang Wang (ORCID: https://orcid.org/0000-0003-2072-2759)
- T. Z. Zhang
- Zouyouwei Lu (ORCID: https://orcid.org/0000-0002-1271-7354)
- Y. H. Zhang
- Q. L. Zhang
- Yining Hu (ORCID: https://orcid.org/0000-0002-9793-2861)
- Rui Wang (ORCID: https://orcid.org/0000-0002-3636-1399)
- Tong Zhang (ORCID: https://orcid.org/0000-0001-6713-3340)
- Di Li (ORCID: https://orcid.org/0000-0003-3010-7661)
- Xianlin Dong (ORCID: https://orcid.org/0000-0003-1374-6648)
- Yun Chen (ORCID: https://orcid.org/0000-0003-3948-5626)
- Yue Liu (ORCID: https://orcid.org/0000-0003-2936-7001)
Institutions
- Tongji University (CN)
- University of Science and Technology of China (CN)
- Zhejiang Normal University (CN)
- Chinese Academy of Sciences (CN)
- Fudan University (CN)
- Hefei University (CN)
- Songshan Lake Materials Laboratory (CN)
- FZU ‒ Institute of Physics of the Academy of Sciences of the Czech Republic (CZ)
- Collaborative Innovation Center of Advanced Microstructures (CN)
- National Synchrotron Radiation Laboratory (CN)
- Institute of Physics (CN)
- University of Chinese Academy of Sciences (CN)
- State Key Laboratory of Surface Physics
- Nanjing University (CN)
Publication Details
- Journal
- Physical Review X
- Published
- 2024-11-08
- DOI
- https://doi.org/10.1103/physrevx.14.041039
- Citations
- 9
- Primary Topic
- Physics of Superconductivity and Magnetism
- Type
- article
- Field-Weighted Citation Impact
- 2.80
Funders
- National Natural Science Foundation of China
- Fudan University
- Science and Technology Commission of Shanghai Municipality
- Natural Science Foundation of Jiangsu Province
- National Key Research and Development Program of China
- Key Research Program of Frontier Science, Chinese Academy of Sciences