Skyrmion lattice structural transition in MnSi.

Area of Science:

• Condensed matter physics
• Materials science
• Topological matter

Background:

• Magnetic skyrmions are particle-like topological excitations with swirling spin textures.
• Their crystallization typically forms triangular lattices, limiting studies on packing degrees of freedom.
• The potential for diverse skyrmion lattice structures remains largely unexplored.

Purpose of the Study:

• To investigate the structural transitions of magnetic skyrmion lattices.
• To explore the formation and properties of metastable skyrmion states.
• To understand the influence of external fields and temperature on skyrmion lattice structures.

Main Methods:

• Utilizing small-angle neutron scattering (SANS) to probe magnetic structures.
• Inducing metastable skyrmion states via thermal quenching.
• Systematically varying temperature and magnetic fields.

Main Results:

• A metastable skyrmion state was observed over a broad temperature and magnetic field range after thermal quenching.
• A structural transition from a triangular to a square skyrmion lattice was induced by decreasing magnetic field at low temperatures.
• The study demonstrated the emergence of various skyrmion lattices at low temperatures.

Conclusions:

• Skyrmion lattices can exhibit structural transitions, specifically from triangular to square lattices.
• The packing and arrangement of skyrmions are sensitive to magnetic field and temperature.
• These findings highlight the potential for diverse topological skyrmion states and their tunable properties influenced by material anisotropy.