Researchers at the Paul Scherrer Institute in Switzerland working with scientists at institutions in Germany, Great Britain, Spain, and the US, have investigated a novel crystalline material, a chiral semimetal, exhibiting never-before-seen electronic properties. These include so-called chiral Rarita-Schwinger fermions in the interior and very long, quadruple topological Fermi arcs on the surface. The crystal, synthesized at the Max Planck Institute for Chemical Physics of Solids in Dresden, Germany, comprises aluminum and platinum atoms arranged in a helical pattern, like a spiral staircase. It’s the crystal’s chiral symmetry that hosts exotic emergent electronic properties.
These research findings, published online in the journal Nature Physics on May 6, 2019, validate a 2016 theoretical prediction by University of Illinois Physics Professor Barry Bradlyn (then a postdoc at the Princeton Center for Theoretical Science), et al., in the journal Science (vol. 353, no. 6299, aaf5037). That theoretical work was subsequently rounded out by a team of physicists at Princeton University, in research published in 2017 and 2018.