Observation of a New Thermoelectric Effect in Superconducting Thin Films

Measurements are reported of a new thermoelectric effect in thin indium-indium-oxide superconducting films. In the temperature regime between the Kosterlitz-Thouless vortex dissociation temperature Tc and the BCS transition temperature Tc0, a simultaneous electric field and temperature gradient cause the film to become weakly magnetized with a magnetization normal to the plane of the film. The magnetization rises to a maximum between Tc and Tc0 and is linear in both the temperature gradient and electric field.