ESPCI web site
Jeudi 27 octobre 14h
Amphi Charpak
Real-space Obstruction in Quantum Spin Hall Insulators
In the hunt for room-temperature quantum spin Hall insulators, bismuthene [1] has demonstrated the impressive advantage of a local spin-orbit coupling experienced by the in-plane p-orbitals. This alternative to pi-bond graphene can be pushed to a conceptually even more essential level upon halving the honeycomb lattice, i.e. considering chiral p-orbitals on a triangular lattice [2]. Here, we theoretically conceive and experimentally realize for the first time a triangular QSHI, indenene, an indium monolayer exhibiting non-trivial valley physics and a large gap. We identify an interference mechanism of the Bloch functions and the emergence of a hidden honeycomb pattern in the charge localization, which makes the topological classification accessible to bulk experiments, without the necessity of quantum edge transport.
[1] F. Reis, G. Li, L. Dudy, M. Bauernfeind, S. Glass, W. Hanke, R. Thomale, J. Schäfer and R. Claessen, Science 357, 287 (2017) https://doi.org/10.1126/science.aai8142
[2] M. Bauernfeind, J. Erhardt, P. Eck, P. K. Thakur, J. Gabel, T.-N. Lee, J. Schäfer, S. Moser, D. Di Sante, R. Claessen and G. Sangiovanni, Nat. Commun. 12, 5396 (2021) https://doi.org/10.1038/s41467-021-25627-y
