The current-voltage I-V characteristics of amorphous W monolayers and W/Si multilayers have been measured at different temperatures below Tc in the absence of magnetic field. For the W monolayer, we observed the power law V ∝ I∝ dependence and a sudden increase of ∝ from 1 to 3 at the Kosterlitz-Thouless transition temperature. However, in the W/Si multilayer, the I-V characteristics obey the modified power law V ∝ I(I-Ic)∝-1 with a non-vanishing critical current Ic This result is ascribed to the effect of interlayer coupling between the W layers on the thermal excitations of vortex-antivortex pairs.
ASJC Scopus subject areas
- Physics and Astronomy(all)