Effects of rattling phonons on the dynamics of quasiparticle excitation in the β-pyrochlore KOs2O6 Superconductor

Y. Shimono, T. Shibauchi, Y. Kasahara, T. Kato, K. Hashimoto, Y. Matsuda, J. Yamaura, Y. Nagao, Z. Hiroi

Research output: Contribution to journalArticlepeer-review

29 Citations (Scopus)

Abstract

Microwave penetration depth λ and surface resistance at 27 GHz are measured in high quality crystals of KOs2O6. Firm evidence for fully gapped superconductivity is provided from λ(T). Below the second transition at Tp∼8K, the superfluid density shows a steplike change with a suppression of effective critical temperature Tc. 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 Tp.

Original languageEnglish
Article number257004
JournalPhysical review letters
Volume98
Issue number25
DOIs
Publication statusPublished - 2007 Jun 22

ASJC Scopus subject areas

  • Physics and Astronomy(all)

Fingerprint Dive into the research topics of 'Effects of rattling phonons on the dynamics of quasiparticle excitation in the β-pyrochlore KOs<sub>2</sub>O<sub>6</sub> Superconductor'. Together they form a unique fingerprint.

Cite this