Flux flow dissipation in superconductors with short coherence length

In superconductors where the coherence length is comparable to the Fermi wavelength, the electronic levels within a vortex core are quantized, and separated by energies of the order of the superconducting gap. The absence of a continuum modifies significantly the energy dissipation due to the motion of vortices. At zero temperature, dissipation is suppressed, and the system shows non ohmic behavior. The I-V characteristics show two distinct regimes. Below a given electric field, I is strongly dependent on V. Flux flow resistivity also shows a marked dependence on temperature, and reaches conventional values near $T_c$.