2006/02/14 by D. E. Galli, L. Reatto
Physics and Astronomy · #Atomic and Subatomic Physics Research #Bose–Einstein condensate #Cold Atom Physics and Bose-Einstein Condensates #Condensed matter physics #Ground state #Materials science #Phase (matter) #Phase diagram #Physics #Quantum mechanics #Quantum, superfluid, helium dynamics #Supersolid #Vacancy defect #cond-mat.other #cond-mat.stat-mech
paper · pdf · doi:10.1103/physrevlett.96.165301
5 pages, 2 figures
arxiv created 2006/02/14 · openalex publication_date 2006/04/26 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
It is pointed out that the simulation computation of energy performed so far cannot be used to decide if the ground state of solid 4He has the number of lattice sites equal to the number of atoms (commensurate state) or if it is different (incommensurate state). The best variational wave function, a shadow wave function, gives an incommensurate state, but the equilibrium concentration of vacancies remains to be determined. We have computed the one-body density matrix in solid 4He for the incommensurate state by means of an exact ground state projector method in which incommensurability occurs spontaneously. We find a vacancy induced Bose-Einstein condensation of about 0.23 atoms per vacancy at a pressure of 54 bar. This means that bulk solid 4He is supersolid at low enough temperature if the exact ground state is incommensurate.