In an international collaboration between two experimental and several theoretical groups led by the condensed matter theory group at UZH, a new understanding of the electronic properties of elementary bismuth has been reached. The researchers found bismuth to be what they call a ‘higher-order topological insulator’. What this means in practice is that bismuth supports conducting states on the hinges of an as-grown crystal. These states have very special properties: they transport electric current — in theory — dissipationless, i.e., without backscattering of the electrons. The theoretical prediction is supported by a scanning-tunneling microscopy experiment and by a transport experiment based on interference in superconducting Josephson junctions. The work was featured on the cover of Nature Physics. 

(https://www.nature.com/articles/s41567-018-0288-4).