Researchers from Twente and Utrecht have made strips of germanium atoms that are one atom thick and a few nanometres wide. The two-dimensional nanoribbons have properties that could be useful in future quantum computers, the authors report in Nature Communications.

Germanene is a two-dimensional layer of germanium atoms just one atom thick, comparable to graphene, which is made up of carbon atoms. Researchers at the University of Twente and Utrecht University have now produced extremely thin strips of germanene, just a few nanometres wide.

Because of their unique structure, these so-called nanoribbons function as two-dimensional topological insulators: although the inside behaves as an insulator, electricity can flow along the edges without any energy loss. And as physicist and PhD student Dennis Klaassen from the University of Twente discovered, in the thinnest nanoribbons, which are only two to three atoms wide, these so-called topological edge states give way to even more special properties. Klaassen: ‘This came as a complete surprise.’