Nanowerk April 3, 2022
Inducing magnetic order in topological insulators via proximity to a magnetic material offers a promising pathway towards achieving quantum anomalous Hall (QAH) effect at higher temperatures for lossless transport applications. An international team of researchers (Australia, Singapore, USA – UC Berkeley) demonstrated the growth of a MnBi2Te4 / Bi2Te3 /MnBi2Te4 heterostructure via molecular beam epitaxy and probed the structure’s electronic structure using angle resolved photoelectron spectroscopy. They observed strong hexagonally warped massive Dirac fermions and a bandgap of 75 ± 15 meV. The 2D MnBi2Te4 ferromagnets induced magnetic order in the ultra-thin topological insulator Bi2Te3 via magnetic proximity. This created a large magnetic gap, with the heterostructure becoming a QAH insulator, such that the material becomes metallic along its one-dimensional edges, whilst remaining electrically insulating in its interior. The almost-zero resistance along the 1D edges of the QAH insulator are what make it such a promising pathway towards next-generation, low-energy electronics…read more. Open Access TECHNICAL ARTICLE
… A schematic showing the realization of the magnetic extension effect in the ferromagnetic insulator… Credit: Advanced Materials, 08 March 2022Â