Non-stationary thermal electromotive force generated by third sound

TL;DR

This paper predicts a non-stationary thermoelectric effect in superfluid films caused by third sound oscillations, resulting in an alternating electric field whose magnitude depends on substrate properties and can surpass metallic EMF levels.

Contribution

It introduces the concept of a non-stationary thermal EMF generated by third sound in superfluid films and analyzes its dependence on substrate and coating methods.

Findings

The thermal EMF can reach up to 10^{-4} V/K.

The effect varies significantly with substrate type.

The predicted EMF exceeds typical metallic thermoelectric voltages.

Abstract

It is predicted that oscillations of temperature during propagation of third sound in a thin superfluid film cause appearance of an alternating electric field in the surrounding space (a peculiar non-stationary thermoelectric effect). The magnitude of this field depends significantly on the substrate type and the method of its coating. It is shown that the differential thermal EMF (the ratio of electric potential amplitude to the film temperature amplitude) can exceed such one in metals and reach $10^{-4}$ V/K.