Complex free-space magnetic field textures induced by three-dimensional magnetic nanostructures

Area of Science:

• Condensed matter physics
• Nanotechnology
• Materials science

Background:

• Designing complex magnetic systems with nonlinear interactions or 3D geometries is key for new functionalities.
• 3D geometries and curvature control intrinsic and geometry-induced properties like anisotropy and chirality, enabling novel spin states and dynamics.
• Controlling interstructure properties, like magnetostatic coupling, is crucial for generating complex magnetic stray field textures.

Purpose of the Study:

• To tailor magnetostatic coupling between neighboring magnetic structures.
• To create complex three-dimensional magnetic stray field textures.
• To explore new functionalities in nanomagnetism.

Main Methods:

• Direct write nanofabrication to create intertwined nanomagnetic cobalt double helices.
• Soft-X-ray magnetic laminography for 3D vectorial magnetic state reconstruction.
• Micromagnetic simulations to analyze magnetization configurations and magnetic induction.

Main Results:

• Successfully fabricated intertwined cobalt double helices exploiting curvature, torsion, chirality, and magnetic coupling.
• Identified a regular array of highly coupled locked domain wall pairs in neighboring helices.
• Observed complex magnetic induction textures, including vortices and antivortices, forming effective B-field cross-tie walls.

Conclusions:

• The design and fabrication of complex 3D magnetic field nanotextures are demonstrated.
• This approach offers new possibilities for smart materials, unconventional computing, particle trapping, and magnetic imaging.
• Tailoring interstructure magnetostatic coupling is a powerful route to engineer advanced magnetic functionalities.