Topological Excitations in Three-band Anisotropic Superconductors

In the recent experimental paper [1] it was reported a disordered-driven transition from the s_± to s₊₊ states in Ba(Fe_1-x Rh_x)₂ As₂.
Theoretically this effect was studied in [2] and the field-induced coexistence of superconducting states in dirty multiband superconductors was investigated in [3].
In [4] a structural change in the morphology of vortex cores was found at the impurity-scattering-driven crossover in two-band superconductors.
We report a study of vortex matter in a three-band model near the s_± to s₊₊ state crossover where the vortex morphology is unusually sensitive to anisotropies, yielding various structural phase transitions in vortex matter.
The work was supported by the Swedish Research Council Grant No. 642-2013-7837 and by Göran Gustafsson Foundation for Research in Natural Sciences and Medicine.

[1] - Ghigo, G. et al., 2018. Physical review letters, 121(10).
[2]- Efremov, D.V. et al., 2011.Physical Review B, 84(18).
[3]- Garaud, J. et al., 2018. Physical Review B, 97(5).
[4]-Garaud, J., et al., 2017. Physical Review B, 96(14).