Magnetic solitons due to interfacial chiral interactions.

Area of Science:

• Condensed Matter Physics
• Magnetism
• Nonlinear Dynamics

Background:

• Magnetic lattices exhibit complex behaviors due to dipole-dipole interactions.
• Chiral interactions, like Dzyaloshinskii-Moriya (DM) coupling, can arise in such systems.
• Solitons are robust, particle-like waves that can propagate without dispersing.

Purpose of the Study:

• To investigate the dynamics of solitons in a specific zig-zag lattice of magnetic dipoles.
• To understand the role of chiral interactions in stabilizing and controlling magnetic solitons.
• To explore the emergence of forces acting on these solitons.

Main Methods:

• Derivation of a long-wavelength Lagrangian density for the easy-axis antiferromagnet.
• Analysis of the dipolar energy, separating it into symmetric and chiral components.
• Modeling the equilibrium magnetic states and the formation of domain walls.

Main Results:

• The system exhibits an equilibrium magnetic state with coupled antiferromagnetic and ferromagnetic chains.
• Dzyaloshinskii-Moriya coupling stabilizes two Bloch domain walls at the edges of the antiferromagnetic chain.
• An effective magnetic field arising from chiral couplings stabilizes the solitons.
• An emergent Lorentz force accelerates the domain walls when sublattices are displaced.

Conclusions:

• Chiral interactions are crucial for the stabilization of magnetic solitons in this zig-zag lattice.
• The interplay between lattice geometry and magnetic interactions leads to emergent forces governing soliton dynamics.
• This system provides a platform for studying controllable soliton propagation in magnetic materials.