Nanowerk February 20, 2021
A team of researchers in the US (MIT, Pennsylvania State University, Argonne National Laboratory, Oak Ridge National Laboratory, NIST, University of Maryland) has shown that due to a new class of Kohn anomaly the topology of the electronic states in a topological material can leave fingerprints on their phonon properties. They experimentally observed it through inelastic x-ray and neutron scattering on WSM (Weyl semimetal) tantalum phosphide. Compared to the conventional Kohn anomaly, the Fermi surface in a WSM exhibits multiple topological singularities of Weyl nodes, leading to a distinct nesting condition with chiral selection, a power-law divergence, and non-negligible dynamical effects. The new approach can be extended to other solid-state materials for the discovery of materials for future quantum devices…read more. TECHNICAL ARTICLEÂ
Energy versus momentum depiction of different conditions that give rise to a Kohn anomaly in ordinary metals (at left), versus a Weyl semimetal (at right). Credit: Mingda Li, MIT.