Lifshitz transition in the double-core vortex in 3He-B

We study the spectrum of fermion states localized within the vortex core of a weak-coupling p-wave superfluid. The low energy spectrum consists of two anomalous branches that cross the Fermi level as functions of the impact parameter, and generate large density of states at the locations of the half cores of the vortex. Fermi liquid interactions significantly change the vortex structure, which leads to Lifshitz transition in the effective Fermi surface of the vortex core fermions. We apply the results to revise the interpretation of an experiment on rotational dynamics of vortices in superfluid 3He-B.Comment: 11 pages, 6 figures, updated to the published versio

Dissipative Currents in Superfluid 3He Weak Links

We calculate the current-pressure relation for pinholes connecting two volumes of bulk superfluid 3He-B. The theory of multiple Andreev reflections, adapted from superconducting weak links, leads to a nonlinear dependence of the dc current on pressure bias. In arrays of pinholes one has to take into account oscillations of the texture at the Josephson frequency. The associated radiation of spin waves from the junction leads to an additional dissipative current at small biases, in quantitative agreement with measurements.Comment: 4 pages, 3 figures; updated to the published versio