We report the electronic structure reconstruction of Ca1−xPrxFe2As2 (x = 0.1 and 0.15) in the low temperature collapsed tetragonal (CT) phase observed by angle-resolved photoemission spectroscopy. Different from Ca(Fe1−xRhx)2As2 and the annealed CaFe2As2 where all hole Fermi surfaces are absent in their CT phases, the cylindrical hole Fermi surface can still be observed in the CT phase of Ca1−xPrxFe2As2. Furthermore, we found at least three well separated electron-like bands around the zone corner in the CT phase of Ca1−xPrxFe2As2, which are more dispersive than the electron-like bands in the high temperature tetragonal phase. Based on these observations, we propose that the weakening of correlations (as indicated by the reduced effective mass), rather than the lack of Fermi surface nesting, might be responsible for the absence of magnetic ordering and superconductivity in the CT phase.
@article{arxiv.1410.6123,
title = {Drastic electronic structure reconstruction of Ca$_{1-x}$Pr$_x$Fe$_2$As$_2$ in the collapsed tetragonal phase},
author = {D. F. Xu and D. W. Shen and J. Jiang and Z. R. Ye and X. Liu and X. H. Niu and H. C. Xu and Y. J. Yan and T. Zhang and B. P. Xie and D. L. Feng},
journal= {arXiv preprint arXiv:1410.6123},
year = {2014}
}