High-Tc cuprate and MgB2 superconductors are recognized as intermediate or strong coupling superconductors. In such a non-weak regime, the vortex core structure is an interesting issue, since the vortex dissipation is expected to be anomalously reduced due to large level distance between localized core states. In this paper, we systematically clarify the vortex core structure based on the fermion-boson model which can cover a full coupling range from weak BCS to strong BEC superconductors. The mean-field calculations on the model reveal that the distances between the low-lying core levels expand and the low-lying states finally disappear when changing the coupling from weak BCS to strong BEC regime. This result suggests that the strong coupling makes the vortex motion non-dissipative.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Energy Engineering and Power Technology
- Electrical and Electronic Engineering