2007/05/17 by Yoshiko Shimono, Y. Shimono, T. Shibauchi +11 · 1 citation
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Nuclear materials and radiation effects #Rare-earth and actinide compounds #cond-mat.str-el #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.98.257004
published as Phys. Rev. Lett. 98, 257004 (2007). · 5 pages, 5 figures, to be published in Phys. Rev. Lett
arxiv created 2007/05/17 · openalex publication_date 2007/06/22 · arxiv updated 2011/11/09 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
Microwave penetration depth lambda and surface resistance at 27 GHz are measured in high quality crystals of KOs(2)O(6). Firm evidence for fully gapped superconductivity is provided from lambda(T). Below the second transition at T(p) approximately 8 K, the superfluid density shows a steplike change with a suppression of effective critical temperature T(c). Concurrently, the extracted quasiparticle scattering time shows a steep enhancement, indicating a strong coupling between the anomalous rattling motion of K ions and quasiparticles. The results imply that the rattling phonons help to enhance superconductivity, and that K sites freeze to an ordered state with long quasiparticle mean free path below T(p).