Possible Effects of 3He Impurities and Shearing on the Formation of Locally Amorphous Supersolid 4He driven by a Pressure Gradient

Abstract

Possible anomalous states of 4He crystal relevant to the possible onset of supersolidity in 4He crystal were reported recently. Here, by treating the 4He crystal locally as an amorphous matter and using the transition-state model together with the specific activation volume as well as activation energy, we observe a series of sudden change of the shearing stresses (which directly relates to the local transport resistance) at corresponding onset temperatures of 4He crystal for different activation volumes considering the role of 3He concentration. We found that once the pressure forcing increases for fixed concentration of 3He the transition temperature decreases which qualitatively agrees with previous results.We also investigate the possible effects of different shear strain rates as well as the pressure gradient upon the nearly frictionless transport of locally amorphous solid 4He within a confined cylindrical domain for a fixed 3He concentration. The tuning of different shear strain rates was found to play a crucial role in the formation of possible supersolidity in 4He crystal.