Topological materials, particularly 2D topological insulators, are of great interest for future electronics and quantum technologies due to their unique property of having an insulating interior but perfectly conductive edges. Topological Quantum Chemistry (TQC) has revolutionized their computational search, although the symmetries in 2D materials have hindered its rigorous application.
An international collaboration, co-first authored by Urko Petralanda (UPV/EHU) and Yi Jiang (DIPC), has adapted TQC to analyze the topology of 2D materials. The study examined 8,872 materials, identifying 4,073 as topological or having similar characteristics. "It's surprising that almost half are topological or obstructed," comments Petralanda.
This adaptation expands the catalog of topological 2D materials, which are fundamental for current and future electronics due to their combinability. A parallel study has identified promising materials for creating twisted bilayers with exotic properties, akin to those found in "magic-angle" graphene.
The new TQC adaptation links chemical composition and crystal symmetries to the topology of electronic states. According to Luis Elcoro (UPV/EHU), "a crystal's symmetry provides rules for how its electronic states can be organized." These tools are made available on the Bilbao Crystallographic Server.
The shared database, involving researcher Nicolas Regnault (Princeton University), allows for the comparison of individual monolayers and the selection of candidates for exploring quantum phenomena, laying the groundwork for this growing research area.
