Clark Bryan K, Ceperley D M
Department of Physics, University of Illinois at Urbana-Champaign, Urbana, 61801, USA.
Phys Rev Lett. 2006 Mar 17;96(10):105302. doi: 10.1103/PhysRevLett.96.105302. Epub 2006 Mar 16.
Measurements of the moment of inertia by Kim and Chan have found that solid (4)He acts like a supersolid at low temperatures. To understand the order in solid 4(He), we have used path integral Monte Carlo simulations to calculate the off-diagonal long-range order (ODLRO) [equivalent to Bose-Einstein condensation (BEC)]. We do not find ODLRO in a defect-free hcp crystal of (4)He at the melting density. We discuss these results in relation to proposed quantum solid trial functions. We conclude that the solid (4)He wave function has correlations which suppress both vacancies and BEC.
