Glide and Superclimb of Dislocations in Solid $^4$He

TL;DR

This paper investigates quantum dislocation dynamics in solid helium-4, revealing how glide and superclimb behaviors depend on temperature, stress, and bias, with phenomena like avalanche creation, hysteresis, and quantum smooth states.

Contribution

It provides a unified quantum simulation of dislocation glide and superclimb in solid helium-4, highlighting new effects like superflow-assisted climb and quantum smooth states at finite temperatures.

Findings

Avalanche-type kink creation at critical stress.

Hysteretic behavior at low temperatures.

Quantum smooth state of superclimb at finite bias.

Abstract

Glide and climb of quantum dislocations under finite external stress, variation of chemical potential and bias (geometrical slanting) in Peierls potential are studied by Monte Carlo simulations of the effective string model. We treat on unified ground quantum effects at finite temperatures $T$. Climb at low $T$ is assisted by superflow along dislocation core -- {\it superclimb}. Above some critical stress avalanche-type creation of kinks is found. It is characterized by hysteretic behavior at low $T$. At finite biases gliding dislocation remains rough even at lowest $T$ -- the behavior opposite to non-slanted dislocations. In contrast to glide, superclimb is characterized by quantum smooth state at low temperatures even for finite bias. In some intermediate $T$-range giant values of the compressibility as well as non-Luttinger type behavior of the core superfluid are observed.