STRONG NONLINEAR GALVANOMAGNETIC EFFECTS IN THIN SUPERCONDUCTING FILMS

We show that in a certain range of parameters the interaction between vortices causes significant enhancement of galvanomagnetic effects in thin superconducting films, as opposed to thick films. In particular, the Nernst coefficient acquires a contribution exceeding the single-vo rtex term at relatively small external magnetic fields. The possibilit y of inducing the dc voltage due to either vortex-antivortex pair prod uction by external ac currents or pair-breaking radiation is also disc ussed. Our results give a possible explanation for the experiments of A. Gerber and G. Deutcher.