Some dislocations in solid He4 have been observed in ab initio simulations to have superfluid core. Accordingly, a question arises how, on one hand, this core superfluidity is affected by dislocation glide and climb, and, on the other, how dislocation motion may be controlled by the core superfluidity. We have proven a theorem that dislocations are smooth at zero temperature and their thermal roughening leads to shear modulus softening at temperatures above the dislocation gap -- energy of the kink-antikink pair. Within a conjecture that dislocation kinks suppress superfluidity it is possible to understand the observed similarity between mechanical and superfluid responses. The phenomenon of superclimb -- non-conservative motion of edge dislocation controlled by superfluid mass transfer along its core -- is also discussed. We predict that this effect leads to giant isochoric compressibility of the crystal at temperatures above the dislocation gap with respect to climb. This prediction can be verified by so called super-syringe experiment.
Host: Haruo Kojima