Half-Quantum Vortices in Nematic and Chiral Phases of 3He
Robert C. Regan, Joshua J. Wiman and J. A. Sauls
- Address: Center for Applied Physics & Superconducting Technologies,
Department of Physics, Northwestern University, Evanston, IL 60208
- Date: May 3, 2021
- Journal: Physical Review X, submitted (2021)
We report theoretical results for the stability of half-quantum vortices (HQVs) in the superfluid phases of \He\ confined in highly anisotropic Nafen aerogel. Superfluidity of 3He confined in Nafen is the realization of a ``nematic superfluid'' with Cooper pairs condensed into a single p-wave orbital aligned along the anisotropy axis of the Nafen aerogel. In addition to the nematic phase, we predict a second ``chiral'' phase that onsets at a lower transition temperature. This chiral phase spontaneously breaks time-reversal symmetry and is a topological superfluid. Both superfluid phases are equal-spin pairing condensates that host arrays of HQVs as equilibrium states of rotating superfluid 3He. We present results for the structure of HQVs, including magnetic and topological signatures of HQVs in both the nematic and chiral phases of 3He-Nafen.
- Comment: 8 pages, 4 figures