Mass Flux Measurements in Solid 4He.*

We previously explored the characteristics of mass flux through solid 4He that takes place from one superfluid-filled reservoir to the other through a solid-filled experimental cell off the melting curve (1). We measured flow characteristics that appear to match expectations for one-dimensional Luttiinger-Liquid conductivity (2) and we documented the effects that various concentrations of 3He impurity have on the temperature dependence of the flow (3). Our most recent experiments show that reducing the interface between superfluid helium in the Vycor rods and solid helium reduces the flux and that significantly blocking the cross section of the channel filled with solid 4He further suppress the flux. These results further support the possibility that the observed mass flux is be due to the superfluid cores of edge dislocations.
(1) M.W. Ray and R.B. Hallock, Phys. Rev. Letters 100, 235301 (2008); 105, 145301 (2010); Phys. Rev. B 79, 224302 (2009); Phys. Rev. B 91, 180506(R) (2015). (2) Ye. Vekhov and R.B. Hallock, Phys. Rev. Letters 109, 045303 (2012); Phys. Rev. B 90, 134511 (2014). (3) Ye. Vekhov, W.J. Mullin and Hallock, Phys. Rev. Letters 113, 035302 (2014); Ye. Vekhov and R.B Hallock, Phys. Rev. B 92, 104509 (2015).