Identifying the 'fingerprint' of antiferromagnetic spin fluctuations in iron pnictide superconductors

被引：36

作者：

Allan, M. P. ^{[1
,2
]}

Lee, Kyungmin ^{[1
]}

Rost, A. W. ^{[1
,3
,4
]}

Fischer, M. H. ^{[1
]}

Massee, F. ^{[1
,2
]}

Kihou, K. ^{[5
,6
]}

Lee, C-H. ^{[5
,6
]}

Iyo, A. ^{[5
,6
]}

Eisaki, H. ^{[5
,6
]}

Chuang, T-M. ^{[7
]}

Davis, J. C. ^{[1
,2
,3
,8
]}

Kim, Eun-Ah ^{[1
]}

机构：

[1] Cornell Univ, Dept Phys, LASSP, Ithaca, NY 14853 USA

[2] Brookhaven Natl Lab, CMPMS Dept, Upton, NY 11973 USA

[3] Univ St Andrews, Sch Phys & Astron, St Andrews KY16 9SS, Fife, Scotland

[4] Univ Tokyo, Dept Phys, Bunkyo Ku, Tokyo 1130033, Japan

[5] Inst Adv Ind Sci & Technol, Tsukuba, Ibaraki 3058568, Japan

[6] JST, Transformat Res Project Iron Pnictides TRIP, Tokyo 1020075, Japan

[7] Acad Sinica, Inst Phys, Taipei 11529, Taiwan

[8] Cornell Univ, Kavli Inst Cornell Nanoscale Sci, Ithaca, NY 14853 USA

来源：

NATURE PHYSICS | 2015年 / 11卷 / 02期

基金：

日本学术振兴会; 英国工程与自然科学研究理事会;

关键词：

Binary alloys - Spin fluctuations - Iron-based Superconductors - Antiferromagnetism - Iron alloys - Electrons - Iron compounds;

D O I：

10.1038/NPHYS3187

中图分类号：

O4 [物理学];

学科分类号：

0702 ;

摘要：

Cooper pairing in the iron-based high-T-c superconductors(1-3) is often conjectured to involve bosonic fluctuations. Among the candidates are antiferromagnetic spin fluctuations(1,4,5) and d-orbital fluctuations amplified by phonons(6,7). Any such electron-boson interaction should alter the electron's 'self-energy', and then become detectable through consequent modifications in the energy dependence of the electron's momentum and lifetime(8-10). Here we introduce a novel theoretical/experimental approach aimed at uniquely identifying the relevant fluctuations of iron-based superconductors by measuring effects of their self-energy. We use innovative quasiparticle interference (QPI) imaging(11) techniques in LiFeAs to reveal strongly momentum-space anisotropic self-energy signatures that are focused along the Fe-Fe (interband scattering) direction, where the spin fluctuations of LiFeAs are concentrated. These effects coincide in energy with perturbations to the density of states N(omega) usually associated with the Cooper pairing interaction. We show that all the measured phenomena comprise the predicted QPI 'fingerprint' of a self-energy due to antiferromagnetic spin fluctuations, thereby distinguishing them as the predominant electron-boson interaction.

引用

页码：177 / 182

页数：6