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arXiv · 0908.4364

Self-energy effects and electron-phonon coupling in Fe-As superconductors

K. -Y. Choi·P. Lemmens·I. Eremin·G. Zwicknagl·H. Berger·G. L. Sun·D. L. Sun·C. T. Lin
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Abstract

We report on Raman scattering experiments of the undoped SrFe2As2 and superconducting Sr0.85K0.15Fe2As2 (Tc=28K) and Ba0.72K0.28Fe2As2 (Tc=32K) single crystals. The frequency and linewidth of the B1g mode at 210 cm-1 exhibits an appreciable temperature dependence induced by the superconducting and spin density wave transitions. We give estimates of the electron-phonon coupling related to this renormalization. In addition, we observe a pronounced quasi-elastic Raman response for the undoped compound, suggesting persisting magnetic fluctuations to low temperatures. In the superconducting state the renormalization of an electronic continuum is observed with a threshold energy of 61cm-1.

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K. -Y. Choi, P. Lemmens, I. Eremin, G. Zwicknagl, H. Berger, G. L. Sun, D. L. Sun, C. T. Lin. 2009-08-29. Self-energy effects and electron-phonon coupling in Fe-As superconductors. https://doi.org/10.1088/0953-8984%2F22%2F11%2F115802

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