Phys.org April 10, 2024
The nexus of topology and interactions yield important research directions. Using tunnelling microscopy, photoemission spectroscopy and a theoretical analysis an international team of researchers (USA – Princeton University, University of Alabama at Birmingham, Florida State University, Oak Ridge National laboratory, UK, Singapore, China, Switzerland) has shown a “hybrid” topological phase of matter in elemental-solid arsenic. They showed that arsenic features a conjoined strong and higher-order topology that stabilizes a hybrid topological phase. Measurements unraveled a unique geometry of topologically induced step-edge conduction channels. Using theoretical models, they showed that the existence of gapless step-edge states in arsenic relies on the simultaneous presence of both a non-trivial strong Z2 invariant and a non-trivial higher-order topological invariant, which provide experimental evidence for hybrid topology. According to the researchers their study highlights pathways for exploring the interplay of different band topologies and harnessing the associated topological conduction channels in engineered quantum or nano-devices… read more. TECHNICAL ARTICLE
Observation of surface state in α-As and its Landau quantization. Credit: Nature, April 10, 2024Â