Cavitation of Electrons Bubbles in Liquid Helium Below saturation Pressure

TL;DR

This study investigates the conditions under which electron bubbles in liquid helium explode under negative pressure, revealing the critical pressures and the influence of temperature, with implications for understanding helium's stability and bubble nucleation.

Contribution

The paper combines a Hartree-type potential with density functional theory to accurately determine the critical pressure for electron bubble explosion in helium, improving upon simpler models.

Findings

Critical pressure closely matches helium's global instability threshold.

Capillary model overestimates critical pressures at high temperatures.

Crossover temperature for thermal to quantum nucleation is around 6 mK.

Abstract

We have used a Hartree-type electron-helium potential together with a density functional description of liquid $^4$He and $^3$He to study the explosion of electron bubbles submitted to a negative pressure. The critical pressure at which bubbles explode has been determined as a function of temperature. It has been found that this critical pressure is very close to the pressure at which liquid helium becomes globally unstable in the presence of electrons. It is shown that at high temperatures the capillary model overestimates the critical pressures. We have checked that a commonly used and rather simple electron-helium interaction yields results very similar to those obtained using the more accurate Hartree-type interaction. We have estimated that the crossover temperature for thermal to quantum nucleation of electron bubbles is very low, of the order of 6 mK for $^4$He.