Boninsegni M, Kuklov A B, Pollet L, Prokof'ev N V, Svistunov B V, Troyer M
Department of Physics, University of Alberta, Edmonton, Alberta T6G 2J1, Canada.
Phys Rev Lett. 2006 Aug 25;97(8):080401. doi: 10.1103/PhysRevLett.97.080401. Epub 2006 Aug 22.
The supersolid state of matter, exhibiting nondissipative flow in solids, has been elusive for 35 years. The recent discovery of a nonclassical moment of inertia in solid 4He by Kim and Chan provided the first experimental evidence, although the interpretation in terms of supersolidity of the ideal crystal phase remains a subject to debate. Using quantum Monte Carlo methods we investigate the long-standing question of vacancy-induced superflow and find that vacancies in a 4He crystal phase separate instead of forming a supersolid. On the other hand, nonequilibrium vacancies relaxing on defects of polycrystalline samples could provide an explanation for the experimental observations.
