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arXiv · 0903.4388

Three- to Two-Dimensional Transition of the Electronic Structure in CaFe2As2 - 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. Budko·P. C. Canfield·A. Kaminski
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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.

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Chang Liu, Takeshi Kondo, Ni Ni, A. D. Palczewski, A. Bostwick, G. D. Samolyuk, R. Khasanov, M. Shi, E. Rotenberg, S. L. Budko, P. C. Canfield, A. Kaminski. 2009-03-25. Three- to Two-Dimensional Transition of the Electronic Structure in CaFe2As2 - parent compound for an iron arsenic high temperature superconductor. https://doi.org/10.1103/physrevlett.102.167004

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