Binding of a 3He impurity to a screw dislocation in solid 4He

TL;DR

This paper uses first-principle simulations to study how 3He impurities bind to screw dislocations in solid 4He, explaining experimental observations of specific heat and shear modulus changes at low temperatures.

Contribution

It provides a detailed quantum-mechanical analysis of 3He binding to dislocations, linking microscopic interactions to macroscopic elastic and thermal properties.

Findings

Binding energy of 3He to dislocation is approximately 0.8 K.

Model reproduces the specific heat peak observed experimentally.

Explores the role of 3He in superfluid defect scenarios.

Abstract

Using first-principle simulations for the probability density of finding a 3He atom in the vicinity of the screw dislocation in solid 4He, we determine the binding energy to the dislocation nucleus E_B = 0.8 \pm 0.1 K and the density of localized states at larger distances. The specific heat due to 3He features a peak similar to the one observed in recent experiments, and our model can also account for the observed increase in shear modulus at low temperature. We further discuss the role of 3He in the picture of superfluid defects.