Tunneling Defect Nanoclusters in hcp 4He Crystals: Alternative to Supersolidity

Abstract

A simple model based on the concept of resonant tunneling clusters of lattice defects is used to explain the low temperature anomalies of hcp 4 He crystals (mass decoupling from a torsional oscillator, shear modulus anomaly, dissipation peaks, heat capacity peak). Mass decoupling is a result of an internal Josephson effect: mass supercurrent inside phase coherent tunneling clusters. Quantitative results are in reasonable agreement with experiments.

Saga of Superfluid Solids

“…For instance, this could be quantum vacancies or interstitials, as has been assumed by Andreev and Lifshitz [35] and others [93][94][95][96][97], dislocations [98], or grain boundaries and surfaces [99][100][101][102]. This can be a nanoporous glass, where a local Bose-Einstein condensation in nanopores is observed [103][104][105], or an amorphous solid with an absolutely irregular structure that is a kind of a glass [106][107][108][109][110][111][112].…”

Saga of Superfluid Solids

“…For instance, this could be quantum vacancies or interstitials, as it has been assumed by Andreev and Lifshits [35] and others [93][94][95][96][97], dislocations [98], or grain boundaries and surfaces [99][100][101][102]. This can be a nanoporous glass, where a local Bose-Einstein condensation in nanopores is observed [103][104][105], or an amorphous solid with an absolutely irregular structure, that is a kind of a glass [106][107][108][109][110][111][112].…”