Elastic constants of solid He-4 under pressure: Diffusion Monte Carlo study

Article

关键词: THERMODYNAMIC PROPERTIES;    SOUND-PROPAGATION;    VOLUME DEPENDENCE;    GROUND-STATE;    HCP PHASE;    HELIUM;    ALGORITHMS;    CRYSTALS;   

DOI  :  10.1103/PhysRevB.85.024101

来源: SCIE

【 摘 要 】

We study the elasticity of perfect solid He-4 at zero temperature using the diffusion Monte Carlo method and a realistic semiempirical pairwise potential to describe the He-He interactions. We calculate the value of the elastic constants of hcp helium {C-ij} as a function of pressure from zero up to similar to 110 bar. It is found that the pressure dependence of all nonzero elastic constants is linearly increasing and we provide accurate parametrization of each of them. Our C-ij results are compared to previous variational calculations and low-temperature measurements and, in general, we find notably good agreement among them. Furthermore, we report results for the Gruneisen parameters, sound velocities, and Debye temperature over a wide range of pressures. This work represents a comprehensive quantum atomistic calculation of the elastic properties of solid helium under compression.

【 授权许可】

Free