Thermoelectrically generated charge imbalance in superconducting aluminum films

Thermoelectrically generated charge imbalance voltages have been measured in superconducting aluminum films. Voltages were measured in seven aluminum samples including two samples containing the magnetic impurity Er. The results obtained from the Al samples support recent theoretical predictions that a quasiparticle charge imbalance distribution is produced in a current carrying superconductor by a temperature gradient. In samples with no magnetic impurities, the observed linear dependence of the charge imbalance voltage on both the current and the temperature gradient as well as a divergence of the voltage near the superconducting transition temperature are in qualitative agreement with theory