Special Physics Seminar

Supersolidity in helium and in cold atoms

Massimo Boninsegni

University of Alberta

The search for the elusive “supersolid” phase of matter continues to engage experimental and theoretical physicists. While agreement on the existing phenomenology is still lacking, theoretical progress is being afforded by large-scale simulations of realistic models of condensed matter systems (solid helium), as well as of assemblies of cold atoms, which hold promise to realize in the laboratory the supersolid and other exotic phases. In this talk, the most robust theoretical predictions regarding the supersolid phase of helium, obtained by Monte Carlo simulations (based on the continuous-space Worm Algorithm introduced in 2006) will be reviewed, with a particular emphasis on the physics of extended defects, such as dislocations, which is likely to hold the key to the understanding of the observed non-classical rotational inertia at low temperature. Also, a different, novel supersolid droplet crystal phase will be described, predicted by simulation for a system of cold atoms with a modified interaction, whose experimental realization appears feasible.