Europhys. Lett, 44 (6), pp. 772-777 (1998)
Electronic vortex structure and flux-flow resistance steps
in the cuprate superconductor
R. P. Huebener, S. Kaiser and O. M. Stoll
Physikalisches Institut, Lehrstuhl Experimentalphysik II
Universität Tübingen, Morgenstelle 14 - D-72076 Tübingen, Germany
(received 2 September 1998; accepted 17 October 1998)
PACS. 74.25Fy - Transport properties (electric and
thermal conductivity, thermoelectric
PACS. 74.60Ge - Flux pinning, flux creep, and flux-line lattice dynamics.
PACS. 74.72Jt - Other cuprates.
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 . 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.