Talks can be found online in the schedule.|
For nearly half a century the supersolid phase of matter has remained
mysterious, not only eluding experimental observation, but also generating
a great deal of controversy. The supersolid phase can be generally defined
as one that combines typical crystalline properties, such as shear modulus
and broken translation symmetry, with frictionless mass transport through
the solid bulk. The striking, simultaneous presence of solid and
superfluid properties in a single-component condensed matter system,
results in a number of phenomena that defy our everyday experience.
Recent discovery by Kim and Chan of what is interpreted as a
non-classical moment of inertia at low temperature in solid He-4 has
elicited much excitement as a possible first observation of a supersolid
phase. Several microscopic mechanisms have been suggested to underlie
superfluidity in a perfect quantum crystal. However, as the initial
experiment is being repeated by other groups, and concurrently different
experiments and microscopic calculations are being carried out things turn
out to be considerably more complicated (and thus more interesting) than
expected. In the two years following the discovery more puzzles than
answers have been provided to the fundamental issue of whether the
supersolid phase exists, in helium or any other naturally occurring
condensed matter system. Presently, there is no established theoretical
framework to understand the body of experimental data, nor there is
consistency between results obtained by different experimental groups.
There are theoretical and experimental results which claim an insulating
crystalline ground state and discuss instead disordered supersolid phases
where superfluidity is induced by defects of the crystalline structure.
This workshop will bring together active researchers in the field, as well as several experts in related fields, to discuss the current status of the supersolid problem in helium, address existing controversies, both experimental and theoretical, and propose new strategies for their resolution. In a broader context, the workshop will look at the perspectives for finding supersolid phases in quantum lattice models, and understanding what interatomic potentials, given the freedom to design one, can support the supersolid phase in continuous space. We expect that the meeting will foster closer collaboration between the theoretical and experimental groups including the design of new experiments to test new ideas about the supersolid state and first-principles simulations of experimentally relevant samples.