Back to Search Start Over

Dislocation Structure and Mobility in hcpHe4

Authors :
Edgar Josué Landinez Borda
Wei Cai
Maurice de Koning
Source :
Physical Review Letters. 117
Publication Year :
2016
Publisher :
American Physical Society (APS), 2016.

Abstract

Using path-integral Monte Carlo simulations, we assess the core structure and mobility of the screw and edge basal-plane dislocations in hcp $^{4}\mathrm{He}$. Our findings provide key insights into recent interpretations of giant plasticity and mass flow junction experiments. First, both dislocations are dissociated into nonsuperfluid Shockley partial dislocations separated by ribbons of stacking fault, suggesting that they are unlikely to act as one-dimensional channels that may display L\"uttinger-liquid-like behavior. Second, the centroid positions of the partial cores are found to fluctuate substantially, even in the absence of applied shear stresses. This implies that the lattice resistance to motion of the partial dislocations is negligible, consistent with the recent experimental observations of giant plasticity. Further results indicate that both the structure of the partial cores and the zero-point fluctuations play a role in this extreme mobility.

Details

ISSN :
10797114 and 00319007
Volume :
117
Database :
OpenAIRE
Journal :
Physical Review Letters
Accession number :
edsair.doi...........4fd1266fadf5bcabc2c60b05d37bbfa8
Full Text :
https://doi.org/10.1103/physrevlett.117.045301