Randomized measurements reveal topological quantum states

Topological materials – materials that have surface properties very different to those found in their bulk – are currently revolutionizing condensed-matter physics thanks to their unique characteristics. Researchers in Austria, France, the US and Germany have now put forward a new technique to identify and characterize the global invariants that mathematically describe these materials in various experimental platforms in the laboratory. The work could advance our understanding of these structures, which might be used in next-generation energy-efficient electronics and quantum computing applications.