Vortex-bound solitons in topological superfluid ${}^3$He

Abstract

The different superfluid phases of ${}^3$He are described by $p$-wave order parameters that include anisotropy axes both in the orbital and spin spaces. The anisotropy axes characterize the broken symmetries in these macroscopically coherent quantum many-body systems. The systems' free energy has several degenerate minima for certain orientations of the anisotropy axes. As a result, spatial variation of the order parameter between two such regions, settled in different energy minima, forms a topological soliton. Such solitons can terminate in the bulk liquid, where the termination line forms a vortex with trapped circulation of mass and spin superfluid currents. Here we discuss possible soliton-vortex structures based on the symmetry and topology arguments and focus on the three structures observed in experiments: solitons bounded by spin-mass vortices in the B phase, solitons bounded by half-quantum vortices in the polar and polar-distorted A phases, and the composite defect formed by a half-quantum vortex, soliton and the Kibble-Lazarides-Shafi wall in the polar-distorted B phase. The observations are based on nuclear magnetic resonance (NMR) techniques and are of three types: first, solitons can form a potential well for trapped spin waves, observed as an extra peak in the NMR spectrum at shifted frequency; second, they can increase the relaxation rate of the NMR spin precession; lastly, the soliton can present the boundary conditions for the anisotropy axes in bulk, modifying the bulk NMR signal. Owing to solitons' prominent NMR signatures and the ability to manipulate their structure with external magnetic field, solitons have become an important tool for probing and controlling the structure and dynamics of superfluid ${}^3$He, in particular half-quantum vortices with core-bound Majorana modes.

arXiv comment46 pages, 23 figures. Review prepared for JPCM special issue on Solitons in quantum physics

References in corpus (46)

• Fault-tolerant quantum computation by anyons
• Non-abelian statistics of half-quantum vortices in p-wave superconductors
• Big bang simulation in superfluid 3He-B -- Vortex nucleation in neutron-irradiated superflow
• Observation of Half Quantum Vortices in an Exciton-Polariton Condensate
• Observation of half-height magnetization steps in Sr2RuO4
• Axion dark matter, solitons, and the cusp-core problem
• Observation of half-quantum vortices in topological superfluid 3He
• Polar phase of superfluid 3He in anisotropic aerogel
• On Phase Ordering Behind the Propagating Front of a Second-Order Transition
• Half-Quantum Vortices in an Antiferromagnetic Spinor Bose-Einstein Condensate
• Monopoles and fractional vortices in chiral superconductors
• Half-quantum vortices and walls bounded by strings in the polar-distorted phases of topological superfluid ${}^3$He
• Composite defect extends cosmology - 3He analogy
• Spin polarization of half-quantum vortex in systems with equal spin pairing
• Orbital glass and spin glass states of 3He-A in aerogel
• Evidence for a Spatially-Modulated Superfluid Phase of ${}^3$He under Confinement
• Phase diagram of superfluid 3He in "nematically ordered" aerogel
• Strong Coupling Corrections to the Ginzburg-Landau Theory of Superfluid ^{3}He
• Symmetry Protected Topological Superfluid ${}^3$He-B
• Observation of wall-vortex composite defects in a spinor Bose-Einstein condensate
• Monopoles, Strings, and Necklaces in $SO(10)$ and $E_6$
• The A-B transition in superfluid 3He under confinement in a thin slab geometry
• Exceeding the Landau superflow speed limit with topological Bogoliubov Fermi surfaces
• Analog of Anderson theorem for the polar phase of liquid 3He in nematic aerogel
• The Superfluid Glass Phase of 3He-A
• Unified Origin of Axion and Monopole Dark Matter, and Solution to the Domain-wall Problem
• Relations among topological solitons
• String monopoles, string walls, vortex-skyrmions and nexus objects in polar distorted B-phase of ${}^3$He
• Suppressing the Kibble-Zurek mechanism by a symmetry-violating bias
• Stability of superfluid 3He-B in compressed aerogel
• Non-Abelian Alice strings in two-flavor dense QCD
• Hard domain walls in superfluid 3He-B
• Triply Charged Monopole and Magnetic Quarks
• Superfluid phases of ${}^3$He in a periodic confined geometry
• Half-quantum vortices in polar phase of superfluid He-3
• Spin, orbital, Weyl and other glasses in topological superfluids
• Stability of Half-Quantum Vortices in Equal-Spin Pairing States of ${}^3$He
• Phase Diagram of Solitons in the Polar Phase of a Spin-1 Bose-Einstein Condensate
• Topological nodal line in superfluid ${}^3$He and the Anderson theorem
• Spin-Current Instability at a Magnetic Domain Wall in a Ferromagnetic Superfluid: a Generation Mechanism of Eccentric Fractional Skyrmions
• Evolution of Neutron-Initiated Micro-Big-Bang in superfluid He 3B
• NMR properties of the polar phase of superfluid He-3 in anisotropic aerogel under rotation
• One dimensional nexus objects, network of Kibble-Lazarides-Shafi string walls, and their spin dynamic response in polar distorted B-phase of ${}^3$He
• Dirac plus Nambu Monopoles in the Standard Model
• Strong-coupling corrections to hard domain walls in superfluid 3He-B
• Linear NMR in the polar phase of ${}^3$He in aerogel

Cited by in corpus (2)

• Composite Topological Structures in SO(10)
• A-B transition in superfluid ${}^3$He and cosmological phase transitions