Microscopic description of stress- and temperature-dependent shear modulus in solid 4He

TL;DR

This paper presents a microscopic model explaining the temperature and stress dependence of the shear modulus in solid helium, accounting for hysteresis and impurity effects through dislocation pinning mechanisms.

Contribution

It introduces a detailed microscopic method to calculate shear modulus anomalies in solid helium considering dislocation pinning by impurities and network nodes.

Findings

Reproduces shear modulus suppression with increasing temperature and stress.

Explains stress hysteresis via path-dependent dislocation pinning.

Highlights the influence of sample preparation on low-temperature shear modulus.

Abstract

We developed a detailed microscopic method that describes the shear modulus anomaly of solid helium at low temperature. The shear modulus was calculated using the pinning length of dislocations determined in detail for both crossing network nodes and 3He impurities. The strong suppression of the shear modulus is reproduced well as the temperature or stress increases. The shear modulus at low temperatures depends strongly on how the state was prepared. All the key features in the stress hysteresis can be quantitatively explained in terms of the thermomechanical path-dependent pinning length of dislocation networks.