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Dislocation Structure and Mobility in hcpHe4
- 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.
- Subjects :
- Physics
Condensed matter physics
Mass flow
Monte Carlo method
General Physics and Astronomy
02 engineering and technology
Plasticity
021001 nanoscience & nanotechnology
01 natural sciences
Condensed Matter::Materials Science
Lattice (order)
0103 physical sciences
Partial dislocations
Dislocation
010306 general physics
0210 nano-technology
Stacking fault
Subjects
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