Laser-induced magnetic nanostructures with tunable topological properties.

Area of Science:

• Condensed matter physics
• Materials science
• Nanotechnology

Background:

• Topological magnetic structures like Skyrmions are crucial for next-generation data storage and spintronic devices.
• Current methods for creating and stabilizing Skyrmions often require external magnetic fields or specific material compositions.

Purpose of the Study:

• To demonstrate the creation of stable, field-free magnetic Skyrmions using ultrashort laser pulses.
• To investigate the tunability of topological magnetic structures by varying laser parameters.
• To provide a theoretical model explaining the stability of these laser-induced magnetic features.

Main Methods:

• Generation of magnetic structures in a thin ferrimagnetic film using single, ultrashort optical laser pulses.
• Real-space observation of the created magnetic structures.
• Development of an analytical model to describe the stability of the magnetic features.

Main Results:

• Successfully created and observed magnetic structures with well-defined topological properties, down to 150 nm in size.
• Demonstrated that these structures are a type of Skyrmion stabilized without an external magnetic field.
• Showed that the topological characteristics of the magnetic features can be tuned by adjusting the laser fluence.
• Validated the stability of these features through an analytical model considering exchange and magnetic dipole-dipole interactions.

Conclusions:

• Ultrashort laser pulses offer a novel method for generating stable, field-free magnetic Skyrmions.
• The laser-induced magnetic structures exhibit tunable topological properties, opening possibilities for advanced magnetic device applications.
• The interplay between exchange and dipole-dipole interactions is key to the stability of these laser-generated topological magnetic features.