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(-).

引用

页数：13

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