Electronic vortex structure of Fe-based superconductors: application to LiFeAs

TL;DR

This paper provides a theoretical analysis of vortex core states in Fe-based superconductors, specifically LiFeAs, using a five-band model and compares the results with experimental STM data.

Contribution

It introduces a realistic five-band model for vortex states in Fe-based superconductors with an $s\,\pm$ gap, matching experimental STM observations.

Findings

Computed local density of states aligns with STM measurements

Reveals detailed vortex core structure in LiFeAs

Supports $s\pm$ pairing symmetry in Fe-based superconductors

Abstract

Detailed tunneling spectroscopy of vortex core states can provide important insight to the momentum structure of the superconducting order parameter. We present a theoretical study of vortex bound states in iron-based superconductors by use of a realistic five-band model relevant to these systems, and superconductivity stabilized by spin-fluctuation generated pairing vertices yielding an $s\pm$ gap structure. The computed local density of states agrees remarkably well with both the bias dependence of the local conductance and the spatial structure of the low-bias conductance as obtained by scanning tunneling microscopy measurements on LiFeAs [T. Hanaguri et al., Phys. Rev. B 85, 214505 (2012)].