Twofold symmetric vortex core states in nematic superconductors with anisotropic Fermi surface and pairing functions
Phys. Rev. B 113, 094520 – Published 19 March, 2026
DOI: https://doi.org/10.1103/27tp-xzjb
Abstract
The twofold symmetric vortex core structure is studied by Eilenberger theory in a type-II superconductor by assuming the nematic superconducting gap as well as the anisotropic effective mass model with an elliptic Fermi surface. We calculate the spatial structures of the pair potential, screening current, internal magnetic field, and local density of states (LDOS) around vortices. We estimate how the anisotropic Fermi surface and the pairing function contribute to the nematic anisotropy ratio of the twofold symmetric vortex core structure. Moreover, the LDOS in the nematic superconductor FeSe is evaluated using the Fermi surface obtained from the tight-binding model in order to reproduce the splitting of the LDOS peak into two parallel distributions with increasing energy. These results suggest that both the anisotropic Fermi surface and the anisotropic pairing function are necessary to understand the anisotropic vortex core structure in nematic superconductors.
