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arXiv · 1006.5468

Eliashberg Analysis of Optical Spectra Reveals Strong Coupling of Charge Carriers to Spin Fluctuations in Superconducting Iron Pnictides

D. Wu·N. Barisic·M. Dressel·G. H. Cao·Z-A. Xu·J. Carbotte·E. Schachinger
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Abstract

The temperature and frequency dependences of the optical conductivity of Co and Ni-doped BaFe2As2 are analyzed and the electron-boson spectral density a2F(w) extracted using Eliashberg's formalism. The characteristic energy of a large peak in the spectrum around 10 meV coincide with the resonance peak in the spin excitation spectra, giving compelling evidence that in iron-based superconductors spin fluctuations strongly couple to the charge carriers and mediate superconductivity. In addition the spectrum is found to evolve with temperature towards a less structured background at higher energies as in the spin susceptibility.

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D. Wu, N. Barisic, M. Dressel, G. H. Cao, Z-A. Xu, J. Carbotte, E. Schachinger. 2010-06-28. Eliashberg Analysis of Optical Spectra Reveals Strong Coupling of Charge Carriers to Spin Fluctuations in Superconducting Iron Pnictides. https://doi.org/10.1103/physrevb.82.144519

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