Observation of thermal electromotive force oscillations versus magnetic vector potential field in superconducting loop with two Josephson SNS junctions

Superconducting loop with two Josephson SNS junctions was investigated. The junctions were biased by a heat flow. A voltage across the junctions was observed when the heat flow exceeded the critical value. This critical heat flow was a periodical function of magnetic flux in the loop. The period and the magnitude of modulation of this curve coincide with the parameters of the dependence of critical current through the same sample upon the magnetic flux in the absence of the heat flow. (author)