Scanning Tunneling Spectroscopy in the Superconducting State and Vortex Cores of the beta-pyrochlore KOs2O6

Abstract

We performed the first scanning tunneling spectroscopy measurements on the pyrochlore superconductor KOs2O6 (Tc = 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 Å, in agreement with the value derived from the upper critical field Hc2. 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.

arXiv comment5 pages, 4 figures, Revtex 4

References in corpus (19)

• Superconductivty without inversion symmetry: MnSi versus CePt_3Si
• Vortex Imaging in the pi-Band of Magnesium Diboride
• New Pyrochlore Oxide Superconductor RbOs2O6
• Extremely strong-coupling superconductivity and anomalous lattice properties in the beta-pyrochlore oxide KOs2O6
• New beta-Pyrochlore Oxide Superconductor CsOs2O6
• Correlation Effects and Structural Dynamics in the $\beta$-Pyrochlore Superconductor KOs${}_2$O${}_6$
• Mass enhancement, correlations, and strong coupling superconductivity in the beta-pyrochlore KOs2O6
• Scanning Tunneling Spectroscopy on the novel superconductor CaC6
• Crystal growth, structural studies and superconducting properties of beta-pyrochlore KOs2O6
• Second Anomaly in the Specific Heat of beta-Pyrochlore Oxide Superconductor KOs2O6
• Thermal Conductivity of the Pyrochlore Superconductor KOs2O6: Strong Electron Correlations and Fully Gapped Superconductivity
• Possible Anisotropic Order Parameter in Pyrochlore Superconductor KOs${}_2$O${}_6$ Probed by Muon Spin Rotation
• Electronic structure properties and BCS superconductivity in beta-pyrochlore oxides: KOs_2O_6
• Frustration in Coupled Rattler System: KOs2O6
• Shape and Motion of Vortex Cores in Bi_2Sr_2CaCu_2O_{8+δ}
• Uncommonly High Upper Critical Field in the Superconducting KOs${}_2$O${}_6$ Pyrochlore
• A second phase transition and superconductivity in the beta-pyrochlore oxide KOs2O6
• Basic Properties of a Vortex in a Noncentrosymmetric Superconductor
• Node-like excitations in superconducting PbMo6S8 probed by scanning tunneling spectroscopy

Cited by in corpus (6)

• Rattling-Induced Superconductiviy in the Beta-Pyrochlore Oxides AOs2O6
• Induced Superconductivity in Graphene Grown on Rhenium
• Skyrmion-(Anti)Vortex Coupling in a Chiral Magnet-Superconductor Heterostructure
• Full Gap Superconductivity in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Probed by Muon Spin Rotation
• Robust zero-energy bound states around a pair-density-wave vortex core in locally noncentrosymmetric superconductors
• Large and homogeneous mass enhancement in the rattling-induced superconductor KOs${}_2$O${}_6$