2008/06/30 by W. Z. Hu, J. Dong, Jing Dong +8 · 279 citations
Chemistry · Materials Science · Physics and Astronomy · #Computer science #Inorganic Chemistry and Materials #Iron-based superconductors research #Physics #Rare-earth and actinide compounds #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.101.257005
published in Physical Review Letters 101(25), 257005 (American Physical Society) · 5 pages, 2 figures; Phys. Rev. Lett. (accepted)
arxiv created 2008/11/21 · openalex publication_date 2008/12/18 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We performed optical spectroscopy measurement on single crystals of BaFe2As2 and SrFe2As2, the parent compounds of FeAs-based superconductors. Both are found to be quite metallic with fairly large plasma frequencies at high temperature. Upon entering the spin-density-wave state, the formation of partial energy gaps was clearly observed with the surprising presence of two different energy scales. A large part of the Drude component was removed by the gapping of Fermi surfaces. Meanwhile, the carrier scattering rate was even more dramatically reduced. We elaborate that the spin-density-wave instability is more likely to be driven by the Fermi surface nesting of itinerant electrons than a local-exchange mechanism.