Three- to Two-Dimensional Transition of the Electronic Structure in CaFe2As2 - parent compound for an iron arsenic high temperature superconductor
cond-mat.supr-con
/ Authors
Chang Liu, Takeshi Kondo, Ni Ni, A. D. Palczewski, A. Bostwick, G. D. Samolyuk, R. Khasanov, M. Shi, E. Rotenberg, S. L. Budko
and 2 more authors
/ Abstract
We use angle-resolved photoemission spectroscopy (ARPES) to study the electronic properties of CaFe2As2 - parent compound of a pnictide superconductor. We find that the structural and magnetic transition is accompanied by a three- to two-dimensional (3D-2D) crossover in the electronic structure. Above the transition temperature (Ts) Fermi surfaces around Gamma and X points are cylindrical and quasi-2D. Below Ts the former becomes a 3D ellipsoid, while the latter remains quasi-2D. This finding strongly suggests that low dimensionality plays an important role in understanding the superconducting mechanism in pnictides.