Observation of Mass Transport through Solid 4He

TL;DR

This paper reports the first observation of mass transport through solid helium-4, indicating superfluid-like flow in solid form, with flow characteristics influenced by pressure and temperature, hinting at hysteresis effects.

Contribution

It introduces a novel experimental setup enabling direct observation of mass flow through solid helium-4, revealing superfluid-like behavior in the solid phase.

Findings

Mass transport observed through solid 4He

Flow exhibits superfluid characteristics

Flow depends on pressure and temperature

Abstract

By use of a novel experimental design, one that provides for superfluid helium in contact with bulk hcp 4He off the melting curve, we have observed the DC transport of mass through a cell filled with solid 4He in the hcp region of the phase diagram. Flow, which shows characteristics of a superflow, is seen to be independent of the method used to grow the solid, but depends on pressure and temperature. The temperature dependence suggests the possibility of hysteresis.