Electronic vortex structure and flux-flow resistance steps in the cuprate superconductor
Physikalisches Institut, Lehrstuhl Experimentalphysik II, Universität Tübingen, Morgenstelle 14 - D-72076 Tübingen, Germany
Accepted: 17 October 1998
For the superconducting mixed state in the clean limit the electronic density of states above and below the Fermi energy is given by the bound states in the vortex core, with the minigap as a prominent feature. Quasiclassically, shows a steep increase near the energy gap Δ. Since provides the phase space for quasiparticle scattering, these features are expected to strongly affect the flux-flow resistance. Our recent observation of two intrinsic flux-flow resistance steps in epitaxial films of are explained in terms of these features of near and , respectively. The instabilities resulting for current-bias from an electric-field–dependent resistance are discussed in general terms.
PACS: 74.25.Fy – Transport properties (electric and thermal conductivity, thermoelectric effects, etc.) / 74.60.Ge – Flux pinning, flux creep, and flux-line lattice dynamics / 74.72.Jt – Other cuprates
© EDP Sciences, 1998