Nonlinear and time-resolved optical study of the 112-type iron-based superconductor parent Ca${}_{1-x}$La${}_x$FeAs${}_2$ across its structural phase transition

J. W. Harter, H. Chu, S. Jiang +2

The newly discovered 112-type ferropnictide superconductors contain chains of As atoms that break the tetragonal symmetry between the $a$ and $b$ axes. This feature eliminates the…