Effect of a uniform magnetic field on the I-V curves of SFFTs

The connection between the effect of a uniform magnetic field on the I-V curves measured on the microbridges of superconducting flux flow transistors and the vortex dynamics is studied with the help of a model assuming that the motion of the vortices is due to a diffusion process. It is shown that the application of the field results in a critical current reduction which depends on the amplitude of the field and the thickness of the film only. As a consequence the effective thickness of the superconducting layer of the studied microbridges can be estimated from I-V measurements carried out with and without applied field.