Electronic structure around a vortex core in iron-based superconductors: Numerical studies of a two-orbital model

Abstract

Based on a two-orbital model and taking into account the presence of impurities, we study theoretically the electronic structure in the vortex cores of iron-pnictide superconducting materials. The vortex is pinned when the impurity is close to the vortex core. The bound states show up for the unpinned vortex. One strong resonant peak at the negative energy is revealed at the vortex center and the peak splits with the dominant weight at the negative energy. For the pinned vortex, the in-gap low-energy features are wiped out by the impurity so that the gaplike feature for the local density of states persists in the vortex. Our results are in good agreement with recent experiments, presenting a consistent explanation for the different electronic structure of the vortex core revealed by experiments on different materials.

Source-reported materials — not catalogue approval

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