Unusual upper critical field in the pyrochlore KOs2O6

Novel vortex distribution in the β-pyrochlore superconductor KOs2O6

By utilizing the micro-Hall probe array, we study the superconducting and the vortex states in a single crystal of KOs2O6 near the first-order transition at Tp ∼ 8 K, which is associated with a change in the rattling motion of K ions. We show that below the first-order transition, the lower critical field exhibits a distinct decrease, suggesting that the electron-phonon coupling is weakened bel...

Effects of Rattling Phonons on the Dynamics of Quasiparticle Excitation in the -Pyrochlore KOs2O6 Superconductor

Correlation effects and structural dynamics in the b-pyrochlore superconductor KOs2O6

Electronic, magnetic, and dynamical properties of superconducting b-pyrochlore KOs2O6 and related RbOs2O6 and CsOs2O6 compounds are calculated and compared with experiment and contrasted with structurally related spinel pyrochlores. The calculated susceptibility Stoner enhancement (110%) and thermal mass enhancement l=2.5–3 reflect moderate but perhaps important Coulomb correlations. The K+ ion...

Unusual angular and temperature dependence of the upper critical field in UPt3.

Upper critical field in anisotropic superconductors.

Anisotropic superconductivity has been studied in a variety of one-dimensional, ' intercalated, s and artificially prepared" " systems. Much of the experimental work in these systems is related to measurements of the temperature and angular dependence of the upper critical fields H, 2. In many cases, the experiments determine the critical field at which surface superconductivity nucleates, i.e....