Vortex-bound solitons in topological superfluid³He

Area of Science:

• Condensed Matter Physics
• Quantum Many-Body Systems
• Superfluidity

Background:

• Superfluid helium-3 (³He) exhibits complex phases described by p-wave order parameters.
• Broken symmetries in these systems lead to degenerate free energy minima.
• Spatial variations between these minima form topological solitons.

Purpose of the Study:

• To discuss soliton-vortex structures in superfluid ³He based on symmetry and topology.
• To focus on three experimentally observed soliton-vortex configurations.
• To highlight the role of solitons in probing and controlling superfluid dynamics.

Main Methods:

• Symmetry and topology arguments to predict soliton-vortex structures.
• Experimental observations using nuclear magnetic resonance (NMR) techniques.
• Analysis of NMR spectral shifts, relaxation rates, and bulk signal modifications.

Main Results:

• Identified three key soliton-vortex structures: spin-mass vortices in B phase, half-quantum vortices (HQVs) in A phases, and composite defects in B phase.
• Observed solitons trapping spin waves, increasing relaxation rates, and modifying bulk NMR signals.
• Demonstrated solitons as crucial for probing and controlling superfluid ³He dynamics, especially HQVs with Majorana modes.

Conclusions:

• Soliton-vortex structures are topological defects in superfluid ³He arising from broken symmetries.
• NMR techniques provide distinct signatures for soliton detection and characterization.
• Solitons are valuable tools for investigating the complex dynamics and properties of superfluid ³He.