A research team at Florida State University recently synthesized a brand-new crystal material. Its internal atomic spins are no longer neatly arranged like traditional magnets, but form a regularly repeating vortex-like "spin texture." It exhibits magnetic behavior that is completely different from conventional magnetic materials. It is considered to be expected to serve high-density data storage, low-energy electronic devices, and future quantum information technology.
The researchers used an ingenious "structure competition" strategy: mixing two compounds with similar chemical compositions but different crystal symmetries - one composed of manganese, cobalt and germanium, and the other composed of manganese, cobalt and arsenic, which are neighbors in the periodic table. The two crystal structures cannot remain completely stable at the junction of components at the same time, resulting in so-called "structural frustration". This instability is "translated" into magnetic "frustration" at the microscopic level, forcing the atomic spins to distort, and eventually spontaneously organize into periodic vortex patterns inside the crystal.
In conventional magnets, a large number of atomic spins point neatly in the same direction like little arrows, or in a simple anti-parallel arrangement, creating the familiar macroscopic magnetism used in devices such as computer hard drives and smartphones. In the new materials discovered by the scientific research team in this work, the spins no longer simply line up, but form more complex ring-like and wave-like structures, the so-called "spin textures", including spiral or cycloidal configurations similar to "skyrmions". This type of topological spin structure is a cutting-edge research hotspot in the fields of condensed matter physics and materials chemistry.
In order to determine this skyrmion-like magnetic structure, the team used the "Splash Neutron Source" user facility of the U.S. Department of Energy's Oak Ridge National Laboratory to conduct precise measurements on the sample on the TOPAZ single crystal neutron diffractometer, and combined it with newly developed data processing and machine learning tools to analyze the complex magnetic structure with high confidence. The researchers pointed out that this ability allows them to not only "discover" strange spin textures, but also move towards "designing and optimizing" these magnetic structures on demand, providing a new path for material design in information and quantum technology.
From the perspective of application prospects, this type of material carrying skyrmion-like spin texture is considered promising for developing hard drives or storage media with higher information density and improving electron transmission efficiency. Since the energy required to control skyrmions through magnetic fields is extremely low, introducing them into electronic or spintronic devices is expected to significantly reduce energy consumption. Especially in large supercomputing systems with thousands or even tens of thousands of processors, the savings in power and cooling costs may be extremely considerable.
In addition, the researchers believe that this design idea based on "structural frustration" may also provide clues for finding materials that can be used to build "fault-tolerant" qubits. The so-called fault-tolerant quantum computing refers to the use of material and structural design to enable quantum information to be stored and operated stably in real environments with noise and errors. It is regarded as the "holy grail" of quantum information processing, and complex spin texture materials are considered to be a potential path to realize such a solution.
Different from the previous route that relied more on "material hunting", this research emphasizes a kind of "chemical thinking": no longer just "searching" candidates with specific symmetry in the known material library, but starting from the intrinsic relationship between structure and spin, actively designing the combination of ingredients and crystal framework to induce the expected magnetic texture. The research team stated that they hope to build a predictive capability - by setting the combination of elements and structures in advance, they can deduce possible new materials and their magnetic characteristics on paper, rather than relying solely on experimental trial and error.
An important additional benefit of this method is that it is expected to greatly expand the selection of raw materials that can be used to produce skyrmion-like spin textures, thereby finding a material system with lower costs, easier crystal growth, and a more robust supply chain, which is more conducive to future large-scale technology applications. The related results were published in the Journal of the American Chemical Society under the title "The emergence of skyrmion-like spin textures in materials originating from structural frustration." The research facilities used include the Florida State University experimental platform and the neutron scattering facility of Oak Ridge National Laboratory, and were funded by the National Science Foundation.
Compiled from /ScitechDaily