TY - JOUR
T1 - Observation of a hidden hole-like band approaching the fermi level in K-doped iron selenide superconductor
AU - Sunagawa, Masanori
AU - Terashima, Kensei
AU - Hamada, Takahiro
AU - Fujiwara, Hirokazu
AU - Fukura, Tetsushi
AU - Takeda, Aya
AU - Tanaka, Masashi
AU - Takeya, Hiroyuki
AU - Takano, Yoshihiko
AU - Arita, Masashi
AU - Shimada, Kenya
AU - Namatame, Hirofumi
AU - Taniguchi, Masaki
AU - Suzuki, Katsuhiro
AU - Usui, Hidetomo
AU - Kuroki, Kazuhiko
AU - Wakita, Takanori
AU - Muraoka, Yuji
AU - Yokoya, Takayoshi
N1 - Funding Information:
The polarization dependent ARPES experiments at HSRC were performed with the approval of HSRC (Proposal Nos. 14-A-21 and 15-A-15). The preliminary ARPES measurements were performed at the Photon Factory and SPring-8 under proposal numbers 2011G086 and 2011B1892, respectively. M.S. was supported by a Grant-in-Aid for JSPS Fellows. This work was also partially supported by Grants-in-Aid for Scientific Research on Innovative Areas "Heavy Electron" (No. 20102003), for Scientific Research (B) (No. 24340079), for Young Scientists (B) (No. 25800205), and also for JSPS Fellows (No. 25009605) from the Ministry of Education, Culture, Sports, Science and Technology of Japan (MEXT). This work was also partially supported by the Program for Promoting the Enhancement of Research Universities from MEXT.
Publisher Copyright:
©2016 The Physical Society of Japan.
PY - 2016/7/15
Y1 - 2016/7/15
N2 - One of the ultimate goals of the study of iron-based superconductors is to identify the common feature that produces the high critical temperature (Tc). In the early days, based on a weak-coupling viewpoint, the nesting between hole- and electron-like Fermi surfaces (FSs) leading to the so-called s± state was considered to be one such key feature. However, this theory has faced a serious challenge ever since the discovery of alkali-metal-doped FeSe (AFS) superconductors, in which only electron-like FSs with a nodeless superconducting gap are observed. Several theories have been proposed, but a consistent understanding is yet to be achieved. Here we show experimentally that a hole-like band exists in KxFe2-ySe2, which presumably forms a hole-like Fermi surface. The present study suggests that AFS can be categorized in the same group as iron arsenides with both hole- and electron-like FSs present. This result provides a foundation for a comprehensive understanding of the superconductivity in iron-based superconductors.
AB - One of the ultimate goals of the study of iron-based superconductors is to identify the common feature that produces the high critical temperature (Tc). In the early days, based on a weak-coupling viewpoint, the nesting between hole- and electron-like Fermi surfaces (FSs) leading to the so-called s± state was considered to be one such key feature. However, this theory has faced a serious challenge ever since the discovery of alkali-metal-doped FeSe (AFS) superconductors, in which only electron-like FSs with a nodeless superconducting gap are observed. Several theories have been proposed, but a consistent understanding is yet to be achieved. Here we show experimentally that a hole-like band exists in KxFe2-ySe2, which presumably forms a hole-like Fermi surface. The present study suggests that AFS can be categorized in the same group as iron arsenides with both hole- and electron-like FSs present. This result provides a foundation for a comprehensive understanding of the superconductivity in iron-based superconductors.
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U2 - 10.7566/JPSJ.85.073704
DO - 10.7566/JPSJ.85.073704
M3 - Article
AN - SCOPUS:84978120480
SN - 0031-9015
VL - 85
JO - Journal of the Physical Society of Japan
JF - Journal of the Physical Society of Japan
IS - 7
M1 - 073704
ER -