1109.6116 (Hsiang-Hsuan Hung et al.)

Anisotropic vortex lattice structures in the FeSe superconductor    [PDF]

Hsiang-Hsuan Hung, Can-Li Song, Xi Chen, Xucun Ma, Qi-kun Xue, Congjun Wu

In the recent work by Song et al. [Science 332, 1410 (2011)], the scanning
tunneling spectroscopy experiment in the stoichiometric FeSe reveals evidence
for nodal superconductivity and strong anisotropy. The nodal structure can be
explained with the extended s-wave pairing structure with the mixture of the
$s_{x^2+y^2}$ and $s_{x^2y^2}$ pairing symmetries. We calculate the anisotropic
vortex structure by using the self-consistent Bogoliubov-de Gennes mean-field
theory. In considering the absence of magnetic ordering in the FeSe at the
ambient pressure, orbital ordering is introduced, which breaks the $C_4$
lattice symmetry down to $C_2$, to explain the anisotropy in the vortex
tunneling spectra.

View original: http://arxiv.org/abs/1109.6116