Half-Quantum Vortex Pair in Polar-distorted B Phase of Superfluid 3He in Aerogels

Abstract

Motivated by the recent observation and argument on a large half-quantum vortex (HQV) pair connencted by a Kibble wall in superfluid 3He in nematic aerogels, we numerically study to what extent a huge HQV pair can intrinsically occur with no pinning effect due to the aerogel structure in the polar-distorted B (PdB) phase of superfluid 3He. By fully examining the impurity-scattering induced pairing vertex, the emergence of Anderson's Theorem in the p-wave superfluid is verified in the two opposite limits, the isotropic and strongly anisotropic limits. Solving numerically the resulting Ginzburg-Landau (GL) free energy in the weak-coupling approximation and by taking account of the Fermi-liquid (FL) corrected gradient terms, the anisotropy dependence of the vortex structure minimizing the free energy is examined. It is found that, close to the transition between the polar and PdB phases, an interplay of the strong anisotropy and the FL correction makes emergence of a large HQV pair in the PdB phase possible, and that, nevertheless, such a large pair easily shrinks deep in the PdB phase, indicating that a pinning effect due to the aerogel structure is necessary in order to keep a large pair size there. The obtained result indicates the validity of the London limit for describing the vortex structure, and a consistency with the picture based on the NMR measurement is discussed.

15 pages, 10 figures. Color maps have been added, and several parts have been corrected

References in corpus (8)

• Half-quantum vortices and walls bounded by strings in the polar-distorted phases of topological superfluid ${}^3$He
• Influence of Magnetic Scattering on Superfluidity of 3He in Nematic Aerogel
• Analog of Anderson theorem for the polar phase of liquid 3He in nematic aerogel
• Superfluid 3He in squeezed nematic aerogel
• Stability of Half-Quantum Vortices in Equal-Spin Pairing States of ${}^3$He
• Impact of Strong Anisotropy on Phase Diagram of Superfluid ${}^3$He in Aerogels
• Two roads to antispacetime in polar distorted B phase: Kibble wall and half-quantum vortex
• Double-Core Vortex Stabilized by Disorder in Superfluid ${}^3$He B Phase in Globally Isotropic Aerogel

Cited by in corpus (8)

• String monopoles, string walls, vortex-skyrmions and nexus objects in polar distorted B-phase of ${}^3$He
• Quantum Elliptic Vortex in a Nematic-Spin Bose-Einstein Condensate
• Non-Abelian Half-Quantum Vortices in ${}^3{P}_2$ Topological Superfluids
• Half-Quantum Vortices in Nematic and Chiral Phases of ${}^3$He
• Impact of Strong Anisotropy on Phase Diagram of Superfluid ${}^3$He in Aerogels
• One dimensional nexus objects, network of Kibble-Lazarides-Shafi string walls, and their spin dynamic response in polar distorted B-phase of ${}^3$He
• Effect of Dipole Energy on Half-Quantum Vortex in Superfluid Polar Phase
• Fibration, Nexus and Cosmological Composite Topological Defects in Uniaxially Disordered Superfluid ${}^3$He