The xene family of two-dimensional topological insulators plays a central role in many proposals for realizing topological electronic, spintronic, and valleytronic devices. These proposals use either the application of electric fields, proximity magnetism and superconductivity, or chemical functionalization to create topological edge modes in xenes. A key drawback of these techniques is their lack of control over the geometry of interfaces between topological regions, a critical aspect of engineering topological devices. In this talk I will present a scheme for engineering topological edge modes in xenes with atomic precision. I will show through first principles calculations that selectively decorating a single sublattice of xenes with adatoms can induce a quantum spin Hall (QSH) to quantum valley Hall (QVH) topological phase transition. Scanning tunneling microscopy can be used to create interfaces between bare QSH and decorated QVH regions, creating atomically precise interfaces hosting topological edge modes. To conclude I will give a brief overview of the many applications of atomically precise edge modes.
Note: this event will be hybrid. The live talk occuring in Loomis 276 will be simultaneously broadcast via Zoom. The Zoom link will be sent to the Graduate Student and PDRA mailing lists. If you are not on one of those lists and are interested in attending, please email Caitlin at ckengle2@illinois.edu for the link.
