Year: 2012
Type: article
Abstract: The elastic properties of hexagonal close-packed ${}^{4}$He samples have been shown to display various anomalies. As the temperature is lowered below $\ensuremath{\sim}$0.2 K, the elastic shear modulus appears to stiffen and the moment of inertia to drop in a concomitant manner. The former phenomenon is taken as evidence for the pinning of dislocations, and the latter for the appearance of supersolidity. The startling close relationship between these two observables is studied within the framework of classical deformable-body mechanics. A model based on the formation by plastic flow of extremely soft quasiplanar, interconnected layers of dislocations is solved analytically and numerically. This model relates quantitatively the change in moment of inertia to the drop in elastic constant and can account for most experimental observations. Other situations, to which its relevance may seem more doubtful, are discussed.
Source: Physical Review B
Author: Eric Varoquaux
Language: English
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W1796337186