Elastic constants and supersolidity in solid hcp 4He
  The elastic constants of solid \textit{hcp} $^4$He are investigated in molar volumes ranging from about melting up to approximately 14 MPa. Properties of interest are determined by averages formed from computed values in configurations sampled by Monte Carlo of a model wave function. Deviations from known elastic relations are reported near the density where the supersolid fraction is maximum. The results offer further evidence that the supersolid state is related to elastic constants anomalies and that both are manifestations of a single physical process. 
Renato Pessoa and M. de Koning and S. A. Vitiello
cond-mat.other cond-mat.mtrl-sci