Thursday, October 22, 2009

Supersolid Helium and anamolous transport

Underlying Mechanism for the Giant Isochoric Compressibility of Solid 4he: Superclimb of Dislocations

authors:
S. G. Söyler,1 A. B. Kuklov,2 L. Pollet,3 N. V. Prokof'ev,1,4 and B. V. Svistunov1,4

In the experiment on superfluid transport in solid 4He [Phys. Rev. Lett. 100, 235301 (2008)], Ray and Hallock observed an anomalously large isochoric compressibility: the supersolid samples demonstrated a significant and apparently spatially uniform response of density and pressure to chemical potential, applied locally through Vycor “electrodes.” We propose that the effect is due to superclimb: edge dislocations can climb because of mass transport along superfluid cores. We corroborate the scenario by ab initio simulations of an edge dislocation in solid 4He at T=0.5 K. We argue that at low temperature the effect must be suppressed due to a crossover to the smooth dislocation.



http://link.aps.org/doi/10.1103/PhysRevLett.103.175301

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