1. Characteristic two-dimensional Fermi surface topology of high-Tc iron-based superconductors
- Author
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Hirofumi Namatame, Yuji Muraoka, Hiroshi Kumigashira, Kenya Shimada, Kanta Ono, Koji Tsubota, Takayoshi Yokoya, Masaki Taniguchi, Kazutaka Kudo, Keita Iba, Masashi Arita, Taihei Jabuchi, Masanori Sunagawa, Minoru Nohara, Junki Sonoyama, Tomohiro Matsushita, Toshihiko Ishiga, and Takanori Wakita
- Subjects
Superconductivity ,Physics ,Multidisciplinary ,Phase (matter) ,Pairing ,Condensed Matter::Superconductivity ,Fermi surface ,Electron ,Spin (physics) ,Topology ,Topology (chemistry) ,Article ,Fermi Gamma-ray Space Telescope - Abstract
Unconventional Cooper pairing originating from spin or orbital fluctuations has been proposed for iron-based superconductors. Such pairing may be enhanced by quasi-nesting of two-dimensional electron and hole-like Fermi surfaces (FS), which is considered an important ingredient for superconductivity at high critical temperatures (high-Tc). However, the dimensionality of the FS varies for hole and electron-doped systems, so the precise importance of this feature for high-Tc materials remains unclear. Here we demonstrate a phase of electron-doped CaFe2As2 (La and P co-doped CaFe2As2) with Tc = 45 K, which is the highest Tc found for the AEFe2As2 bulk superconductors (122-type; AE = Alkaline Earth), possesses only cylindrical hole- and electron-like FSs. This result indicates that FS topology consisting only of two-dimensional sheets is characteristic of both hole- and electron-doped 122-type high-Tc superconductors.
- Published
- 2013