6533b7d1fe1ef96bd125cd11
RESEARCH PRODUCT
On quantum effects near the liquid-vapor transition in helium
Erik LuijtenMartin H. Müsersubject
PhysicsInternal energyCondensed matter physicsStatistical Mechanics (cond-mat.stat-mech)Lambda transitionGeneral Physics and Astronomychemistry.chemical_elementFOS: Physical sciencesCondensed Matter - Soft Condensed MatterRadial distribution functionSuperfluidityMolecular dynamicschemistryCritical point (thermodynamics)Virial expansionSoft Condensed Matter (cond-mat.soft)Physical and Theoretical ChemistryCondensed Matter - Statistical MechanicsHeliumdescription
The liquid-vapor transition in He-3 and He-4 is investigated by means of path-integral molecular dynamics and the quantum virial expansion. Both methods are applied to the critical isobar and the critical isochore. While previous path-integral simulations have mainly considered the lambda transition and superfluid regime in He-4, we focus on the vicinity of the critical point and obtain good agreement with experimental results for the molar volume and the internal energy down to subcritical temperatures. We find that an effective classical potential that properly describes the two-particle radial distribution function exhibits a strong temperature dependence near the critical temperature. This contrasts with the behavior of essentially classical systems like xenon, where the effective potential is independent of temperature. It is conjectured that, owing to this difference in behavior between classical and quantum-mechanical systems, the crossover behavior observed for helium in the vicinity of the critical point differs qualitatively from that of other simple liquids.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2001-05-14 |