2007/04/04 by C. Dubois, G. Santi, I. Cuttat +12 · 10 citations
Materials Science · Physics and Astronomy · #Advanced Condensed Matter Physics #Anisotropy #Coherence length #Condensed matter physics #Critical field #Iron-based superconductors research #Magnetic field #Materials science #Physics #Physics of Superconductivity and Magnetism #Pyrochlore #Quantum mechanics #Quantum tunnelling #Scanning tunneling spectroscopy #Spectroscopy #Superconductivity #Thermodynamics #Vortex #Vortex state #cond-mat.supr-con
paper · pdf · doi:10.1103/physrevlett.101.057004
published in Physical Review Letters 101(5), 057004 (American Physical Society) · 5 pages, 4 figures, Revtex 4
arxiv created 2007/04/04 · openalex publication_date 2008/07/30 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We performed the first scanning tunneling spectroscopy measurements on the pyrochlore superconductor KOs2O6 (T(c)=9.6 K) in both zero magnetic field and the vortex state at several temperatures above 1.95 K. This material presents atomically flat surfaces, yielding spatially homogeneous spectra which reveal fully gapped superconductivity with a gap anisotropy of 30%. Measurements performed at fields of 2 and 6 T display a hexagonal Abrikosov flux line lattice. From the shape of the vortex cores, we extract a coherence length of 31-40 A, in agreement with the value derived from the upper critical field H(c2). We observe a reduction in size of the vortex cores (and hence the coherence length) with increasing field which is consistent with the unexpectedly high and unsaturated upper critical field reported.