We have studied the reflectance of the recently discovered superconductor LaO_0.9F0.FeAs in a wide energy range from the far infrared to the visible regime. We report on the observation of infrared active phonons, the plasma edge (PE) and possible interband transitions. On the basis of this data and the reported in-plane penetration depth lambda_L(0) about 254 nm [H. Luetkens et al., Phys. Rev. Lett. v. 101, 0970009 (2008)] a disorder sensitive relatively small value of the total electron electron-boson coupling constant lambda_tot=lambda_e-ph+lambda_e-sp ~ 0.6 +- 0.35 can be estimated adopting an effective single-band picture.
@article{arxiv.0805.1321,
title = {Optical Study of LaO_0.9F_0.1FeAs: Evidence for a Weakly Coupled Superconducting State},
author = {S. -L. Drechsler and M. Grobosch and K. Koepernik and G. Behr and A. Koehler and J. Werner and A. Kondrat and N. Leps and Ch. Hess and R. Klingeler and R. Schuster and B. Buechner and M. Knupfer},
journal= {arXiv preprint arXiv:0805.1321},
year = {2009}
}
Comments
Changed title, updated references, final published version