A shadow gap in the over-doped (Ba1-XKX)Fe2As2 compound

被引：41
作者：
Bang, Yunkyu [1 ,2 ]
机构：
[1] Chonnam Natl Univ, Dept Phys, Kwangju 500757, South Korea
[2] Asia Pacific Ctr Theoret Phys, Pohang 790784, South Korea
来源：
NEW JOURNAL OF PHYSICS | 2014年 / 16卷
基金：
新加坡国家研究基金会;
关键词：
Fermi surface instability; iron-based superconductor; pairing symmetry; Fe2As2; nodal gap; SUPERCONDUCTIVITY;
D O I：
10.1088/1367-2630/16/2/023029
中图分类号：
O4 [物理学];
学科分类号：
0702 ;
摘要：
The electron band around the M point in the (Ba1-xKx) Fe2As2 compound, which is completely lifted up above the Fermi level for x > 0.7 and hence its Fermi surface (FS) disappears, can still play the role of the main pairing resource by exchanging inter-band repulsive interaction with the main hole band (h1) around the Gamma point. This hidden electron band, which develops the superconducting order parameter (OP) Delta(e) but has no FS, displays a shadow gap feature which is easily detected by various experimental probes such as angle-resolved photo-emission spectroscopy (ARPES) and tunneling measurements. We also show that the formation of the nodal gap Delta(nodal) with A(1g) symmetry on another hole pocket (h2) around the Gamma point with a larger FS is stabilized due to the balance of the inter-band repulsive interactions from the main hole band (h1) with the OP Delta(h1) = Delta(+), and the hidden electron band with the OP Delta(e) = Delta(-).
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页数：13
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