On the existence of supersolid helium-4 monolayer films

TL;DR

This study uses Monte Carlo simulations to investigate whether helium-4 monolayer films can exhibit supersolid behavior, finding no evidence for supersolidity on strong substrates and liquid growth on weaker ones.

Contribution

First comprehensive Monte Carlo simulation study examining supersolid phases in helium-4 monolayers on various substrates.

Findings

Helium-4 does not form a supersolid monolayer on strong substrates.

On weak substrates, helium-4 forms a continuous liquid film.

Crystalline films are only observed without substrate influence.

Abstract

Extensive Monte Carlo simulations of helium-4 monolayer films adsorbed on weak substrates have been carried out, aimed at ascertaining the possible occurrence of a quasi-two-dimensional supersolid phase. Only crystalline films not registered with underlying substrates are considered. Numerical results yield strong evidence that helium-4 will not form a supersolid film on {any} substrate strong enough to stabilize a crystalline layer. On weaker substrates, continuous growth of a liquid film takes place.