Three- to two-dimensional transition of the electronic structure in CaFe2As2: a parent compound for an iron arsenic high-temperature superconductor

Chang Liu; Takeshi Kondo; Ni Ni; A D Palczewski; A Bostwick; G D Samolyuk; R Khasanov; M Shi; E Rotenberg; S L Bud'ko; P C Canfield; A Kaminski

doi:10.1103/PhysRevLett.102.167004

Three- to two-dimensional transition of the electronic structure in CaFe2As2: a parent compound for an iron arsenic high-temperature superconductor

Phys Rev Lett. 2009 Apr 24;102(16):167004. doi: 10.1103/PhysRevLett.102.167004. Epub 2009 Apr 24.

Authors

Chang Liu¹, Takeshi Kondo, Ni Ni, A D Palczewski, A Bostwick, G D Samolyuk, R Khasanov, M Shi, E Rotenberg, S L Bud'ko, P C Canfield, A Kaminski

Affiliation

¹ Ames Laboratory and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.

PMID: 19518747
DOI: 10.1103/PhysRevLett.102.167004

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 (T_{s}) Fermi surfaces around Gamma and X points are cylindrical and quasi 2D. Below T_{s}, the Gamma pocket forms a 3D ellipsoid, while the X pocket remains quasi 2D. This finding strongly suggests that low dimensionality plays an important role in understanding the superconducting mechanism in pnictides.