Supersolid induced by dislocations with superfluid cores (Review article)

TL;DR

This review discusses the dislocation model of supersolidity in helium-4, highlighting experimental and theoretical advances that support the idea of dislocation cores as superfluid channels and exploring related phenomena.

Contribution

It provides a comprehensive review of the development and current understanding of dislocation-induced supersolidity in helium-4, including new concepts like superclimb and the syringe effect.

Findings

Dislocation cores can host superfluidity in helium-4.

Experimental evidence supports the dislocation model of supersolidity.

Theoretical models explain phenomena like superclimb and giant isochoric compressibility.

Abstract

Dislocation model of the supersolid state of $^4$He was proposed in 1987 by one of the authors of the review. The model obtained strong support by numerous experimental and theoretical investigations from 2007 to date. In these investigations the validity of the idea put forward in 1987 was confirmed, and new conceptions of superclimb of dislocations and of the giant isochoric compressibility or the syringe effect were proposed. In this paper we review main achievements of theoretical and experimental studies of dislocation-induced supersolid and present current understanding of this phenomenon.