Chinese University Develops Atomic-Scale Spin Imaging Method
Researchers at the University of Science and Technology of China have developed a new method for imaging electron spin at the atomic scale using a topological material probe tip. The technique enables more detailed studies of quantum materials.
A research team at the University of Science and Technology of China (USTC) has developed a novel method for imaging electron spin at the atomic scale. The study, published on October 13 in the journal Nature, utilizes a scanning tunneling microscope tip fabricated from a topological material. This "atomic-scale magnifying glass" offers unprecedented detail into the magnetic properties of quantum materials.
Traditional spin-resolving probes often rely on magnetic atoms at the tip, whose spin states can be influenced by interactions with the sample. They also frequently require external magnetic fields. The new method leverages the one-dimensional boundary states of quantum spin Hall systems, which possess a helical characteristic: electrons traveling in opposite directions along the same boundary carry opposite spins.
The research team, in collaboration with the Hong Kong University of Science and Technology, fabricated an atomically resolved scanning tunneling microscope tip from a topological material, specifically single-crystal α-bromobismuth. After confirming the tip's properties, it was used to investigate the surface of potassium vanadium selenide oxide (KV2Se2O). This material study provided evidence of a two-dimensional, d-wave-like, staggered magnetic order at the atomic level.
This advancement opens new avenues for the study of quantum materials and nanoscale magnetic phenomena. The researchers suggest the method could be applied in the future to investigate the properties of emerging materials, including two-dimensional magnets and other complex quantum materials, at the atomic scale.