Fermi-Surface Reconstruction and Complex Phase Equilibria in   CaFe$_{2}$As$_{2}$
  Fermi-surface topology governs the relationship between magnetism and superconductivity in iron-based materials. Using low-temperature transport, angle-resolved photoemission, and x-ray diffraction we show unambiguous evidence of large Fermi surface reconstruction in CaFe$_{2}$As$_{2}$ at magnetic spin-density-wave and nonmagnetic collapsed-tetragonal ($cT$) transitions. For the $cT$ transition, the change in the Fermi surface topology has a different character with no contribution from the hole part of the Fermi surface. In addition, the results suggest that the pressure effect in CaFe$_{2}$As$_{2}$ is mainly leading to a rigid-band-like change of the valence electronic structure. We discuss these results and their implications for magnetism and superconductivity in this material. 
K. Gofryk, B. Saparov, T. Durakiewicz, A. Chikina, S. Danzenb\"acher,   D. V. Vyalikh, M. J. Graf, and A. S. Sefat
cond-mat.str-el