Quasi-2D liquid 3He.
Quantum Monte Carlo simulations at zero temperature of an ensemble of 3He atoms adsorbed on Mg and Alkali substrates yield strong evidence of a thermodynamically stable liquid 3He monolayer on all Alkali substrates, with the possible exception of Li. The effective two-dimensional density is θ≈0.02  Å-2 on Na, making it the lowest density liquid in nature. Its existence is underlain by zero-point atomic motion perpendicular to the substrate, whose effect is softening the short-range repulsion of the helium interatomic potential. The monolayer films should turn superfluid at a temperature Tc∼1  mK. No liquid film is predicted to form on Mg, or on stronger substrates such as graphite.
SISSA Scuola Internazionale Superiore di Studi Avanzati and DEMOCRITOS National Simulation Center, Istituto Officina dei Materiali del CNR Via Bonomea 265, I-34136 Trieste, Italy.
Michele
M
Ruggeri
Saverio
S
Moroni
Massimo
M
Boninsegni