Some mechanisms of "spontaneous" polarization of superfluid He-4

TL;DR

This paper explores how temperature and density gradients induce volume polarization in superfluid helium-4 through a tidal mechanism, linking gravitational effects and observed electric signals to atomic dipole moments.

Contribution

It demonstrates that gradients in superfluid helium-4 cause partial ordering of atomic dipoles, leading to measurable polarization and connecting it to gravitational and thermal effects.

Findings

Earth's gravity induces a measurable electric potential in He-II.

Temperature gradients can cause partial ordering of atomic dipoles.

The observed electric signals relate to polarization effects in superfluid helium.

Abstract

Previously, a quantum "tidal" mechanism of polarization of the atoms of He-II was proposed, according to which, as a result of interatomic interaction, each atom of He-II acquires small fluctuating dipole and multipole moments, oriented chaotically on the average. In this work, we show that, in the presence of a temperature or density gradient in He-II, the originally chaotically oriented tidal dipole moments of the atoms become partially ordered, which results in volume polarization of He-II. It is found that the gravitational field of the Earth induces electric induction U =10(-7)V in He-II (for vessel dimensions of the order of 10 cm). We study also the connection of polarization and acceleration, and discuss a possible nature of the electric signal dU = kdT/2e observed by A.S. Rybalko in experiments with second sound.