@article{6f60995adcc54ee1b6011c80fc1bf7a6,
title = "Identifying the 'fingerprint' of antiferromagnetic spin fluctuations in iron pnictide superconductors",
abstract = "Cooper pairing in the iron-based high-T c superconductors is often conjectured to involve bosonic fluctuations. Among the candidates are antiferromagnetic spin fluctuations and d-orbital fluctuations amplified by phonons. 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. 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 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(ω) 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.",
author = "Allan, {M. P.} and Kyungmin Lee and Rost, {A. W.} and Fischer, {M. H.} and F. Massee and K. Kihou and Lee, {C. H.} and A. Iyo and H. Eisaki and Chuang, {T. M.} and Davis, {J. C.} and Kim, {Eun Ah}",
note = "Funding Information: We are especially grateful to A. P. Mackenzie and D. J. Scalapino for key guidance with this project. We acknowledge and thank D. H. Lee, A. Chubukov, P. J. Hirschfeld, M. Norman and J. Schmalian for helpful discussions and communications. Theoretical studies are supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Materials Science and Engineering under Award DE-SC0010313 (K.L. and E-A.K.); NSF DMR-1120296 to the Cornell Center for Materials Research and NSF CAREER grant DMR-0955822 (M.H.F.). Experimental studies are supported by the Center for Emergent Superconductivity, an Energy Frontier Research Center, headquartered at Brookhaven National Laboratory and funded by the US Department of Energy, under DE-2009-BNL-PM015; by the UK EPSRC; by a Grant-in-Aid for Scientific Research C (No. 22540380) from the Japan Society for the Promotion of Science. T-M.C. acknowledges support by NSC101-2112-M-001-029-MY3. Publisher Copyright: {\textcopyright} 2015 Macmillan Publishers Limited.",
year = "2015",
month = jan,
day = "1",
doi = "10.1038/nphys3187",
language = "English",
volume = "11",
pages = "177--182",
journal = "Nature Physics",
issn = "1745-2473",
publisher = "Nature Publishing Group",
number = "2",
}