In a groundbreaking study, scientists at the National Institute of Standards and Technology (NIST), along with their colleagues, have revolutionized the field of information processing by using neutron imaging and a novel reconstruction algorithm. Through their findings, they have successfully unveiled the elusive 3D shapes and dynamics of magnetic skyrmions, which hold immense potential for energy-efficient data storage and processing.
The conventional method of information processing, which relies on electrical charge states, is plagued by constant refreshment needs and high energy consumption. In stark contrast, manipulating and storing information in stable magnetic states, such as skyrmions, can significantly reduce energy requirements and enable faster switching times. This captivating field of research, known as spintronics, utilizes the inherent magnetic polarity of atomic particles and nanostructures instead of electric charge.
The NIST-led team has specifically focused on magnetic skyrmions, vortex-like formations of atoms that naturally occur in certain atomic lattices. Skyrmions range in size from 20 to 200 nanometers, making them significantly smaller than a human hair. While in two dimensions, they take the shape of disks with atoms’ individual magnetic fields pointing in different directions, in bulk materials, they stack up vertically to form 3D tubes that extend to the material’s top and bottom surfaces.
Despite their immense potential, skyrmion tubes do not consistently maintain their shapes due to defects and asymmetries in the surrounding lattice. These imperfections cause the tubes to curve, twist, bifurcate, or terminate, thus hindering their effective utilization for information storage. The NIST team’s primary aim is to comprehend the underlying causes and develop techniques to control and manipulate these magnetic formations.
To investigate the shapes and propagation of the skyrmion tubes, the researchers devised a unique experimental approach. First, they created bulk samples containing the 3D stacks of skyrmions using a lattice of cobalt, zinc, and manganese. These samples were subjected to neutron tomography, a process that involves directing a beam of neutrons at the sample. The interaction between the neutrons and the skyrmion tubes resulted in scattering, providing valuable information on the shapes of the tubes.
In order to reconstruct a comprehensive 3D image of the skyrmion tubes, the researchers rotated the sample incrementally while being exposed to a magnetic field. This process generated a series of “slices” which were then combined using a sophisticated shape-reconstruction algorithm. The resulting image shed light on the intricate relationship between the shapes and propagation of skyrmion tubes and various localized defects in the lattice.
By gaining a deeper understanding of the impact of defects on the shape of skyrmion tubes, the research team aims to fine-tune future materials for spintronics applications. The ability to visualize and manipulate these fascinating magnetic formations will pave the way for the development of highly efficient storage devices with significantly higher data density. In the near future, consumers may have access to hard drives built on spintronic properties that offer unparalleled performance and efficiency.
The NIST-led research provides a pioneering glimpse into the world of magnetic skyrmions, shedding light on their elusive 3D shapes and dynamics within bulk materials. By harnessing the power of neutron imaging and innovative reconstruction algorithms, scientists have made significant strides in understanding and manipulating these atomic marvels. Their work holds tremendous promise for the future of information processing, paving the way for energy-efficient and high-capacity data storage devices that will revolutionize the field of technology.