Giorgio Sangiovanni

Affiliation: Julius-Maximilians-Universität Würzburg
Research Interests: condensed matter theory
Title: Real-space Obstruction in Quantum Spin Hall Insulators
Abstract: 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.