Spintronics aims to use complex magnetic structures such as magnetic bubbles, skyrmions, and magnetic vortices to store data or perform logic operations with low power consumption. However, the generation and stabilization of these structures is limited to specific materials and conditions. A new approach developed by an international collaboration led by Dr. Sergio Valencia involves creating and stabilizing radial vortices using superconducting structures and surface defects.
In this new approach, micrometer-sized islands of the high-temperature superconductor YBCO are used as the base for depositing a ferromagnetic compound. When the sample is cooled below 92 Kelvin, YBCO enters the superconducting state and an external magnetic field is applied and removed, allowing magnetic flux quanta to penetrate and pin, creating a magnetic stray field that forms radial vortices in the overlying ferromagnetic layer.
As the temperature is increased and YBCO transitions from superconducting to normal state, the stray field created by the superconducting structures should disappear, leading to the disappearance of the magnetic radial vortices. However, the presence of surface defects prevents this from happening, allowing the radial vortices to partially retain their imprinted state even at room temperature.
The team has shown that using the magnetic field generated by the superconducting structures and surface defects to imprint and stabilize magnetic domains on ferromagnetic materials results in structures similar to skyrmions. These imprinted vortices are about 2 micrometers in diameter, larger than typical skyrmions, and circular geometries increase their stability, making them suitable for spintronic applications in a variety of ferromagnetic materials.
This novel approach offers new prospects for the development of superconducting spintronics by creating and stabilizing complex spin textures such as radial vortices in various materials. By leveraging superconducting structures and surface defects, researchers have shown the potential to use these unique magnetic structures for efficient data storage and logic operations with minimal power consumption. This research opens up new possibilities for the advancement of spintronics technology.
