In a groundbreaking study, scientists at the National Institute of Standards and Technology (NIST) have utilized state-of-the-art neutron imaging techniques to gain unprecedented insights into the 3D shapes and behaviors of atomic magnetic arrangements known as skyrmions. Skyrmions have the potential to revolutionize information processing and storage due to their unique properties and ability to consume significantly less energy than current methods. This innovative research field, known as spintronics, harnesses the inherent magnetic polarity of atomic particles and nanostructures to manipulate and store information. The NIST-led team focuses on investigating magnetic skyrmions, a vortex-like arrangement of atoms that occurs naturally in certain atomic lattices in response to magnetic and electrical properties.
One of the main challenges in utilizing skyrmions for practical applications is the need to understand and control the complex 3D shapes formed by these atomic arrangements. Skyrmions in bulk materials often adopt the shape of tubes that can extend from the top to the bottom surfaces of the material. However, these tubes frequently exhibit irregularities, such as curvatures, twists, bifurcations, or terminations, due to defects and asymmetries in the surrounding lattice. Consequently, the NIST team aims to unravel the factors responsible for these effects and develop methods to manipulate the material and exert control over the skyrmion shapes.
To gain insight into the dynamics and shapes of skyrmions, the NIST team collaborated with researchers from the University of Waterloo to create bulk samples containing 3D stacks or tubes of skyrmions in a cobalt, zinc, and manganese lattice. These samples were subjected to a novel form of neutron tomography, where a beam of neutrons was directed at the material. The neutrons scattered off the tubes within the lattice in different directions depending on their shape, allowing the researchers to collect valuable data. By incrementally rotating the sample and combining the resulting “slices” using a shape-reconstruction algorithm, the team was able to create precise 3D images of the skyrmion tubes.
The study provided valuable insights into the relationship between localized defects in the lattice and the shapes of skyrmion tubes. In a perfect crystal, straight tubes would permeate from surface to surface. However, the presence of crystal and magnetic defects disrupts this ideal configuration. The researchers were able to visually observe and analyze the impact of various types of defects on the shape and propagation of skyrmion tubes. This understanding opens up exciting possibilities for fine-tuning future materials for spintronics applications.
The implications of utilizing spintronic properties, such as those exhibited by skyrmions, in practical devices are tremendous. With the ability to store and process information using stable magnetic states, spintronics could significantly reduce the energy consumption associated with conventional semiconductor-based methods. Furthermore, the faster switching time between different states could lead to more efficient and powerful computing systems.
The NIST team’s groundbreaking research is paving the way for a future where spintronic-based hard drives and other devices are commonplace. With the increasing demand for higher storage densities and energy-efficient computing, the potential applications of spintronics are only beginning to be explored. As the field continues to advance, we can anticipate a new era of electronics that harnesses the power of magnetism and atomic structures to revolutionize technology and improve our daily lives.