Chiral superfluid phase of liquid He3 in planar aerogels

Abstract

Motivated by the realization of the chiral superfluid phase of liquid $^{3}\mathrm{He}$ stabilized at lower pressures and over a wide temperature range in planar aerogels, we examine equilibrium properties of the superfluid $A$ phase suffering from impurity scatterings due to planar correlated defects. In the specular limit of scattering due to the planar defects, an analog of Anderson's theorem for the $s$-wave Fermi superfluid is well satisfied in the chiral $A$ phase in the planar aerogels just like in the polar phase in nematic aerogels, and the chiral $A$ phase region is extended by such a planar anisotropy even with no strong coupling correction. It is also pointed out that the vortex energy in the chiral $A$ phase depends on the relative sense of the vorticity to the chirality. Based on this result, it is argued that, due to the presence of chiral domains induced by the randomness, the vortex lattice structure shows broken time-reversal symmetry and may include vortex loops.