Feb 18, 2021
Research : A charge-density-wave topological semimetal
The boundary states of neptunium bismuth (NpBi), an ideal magnetic topological insulator discovered in the presented study.
Topological materials are characterised by unique electronic and physical properties that are determined by the underlying topology of their electronic systems. An international team of scientists has now discovered the first example of a correlation-driven topological semimetal to insulator phase transition in single crystals of the material (TaSe4)2I using a sophisticated combination of experimental and theoretical techniques. (TaSe4)2I was found to be a particular type of metal called Weyl semimetal which on cooling displays a periodic variation of the electronic charge density and the atomic positions in the crystal structure. The formation of this charge density wave is driven by electron correlations and intimately connected to the topological properties. Such materials may open the avenue to future electronic devices which are based on a novel type of coupling between electric and magnetic fields, the so-called axion electrodynamics.
W. Shi, B. J. Wieder, H. L. Meyerheim, Y. Sun, Y. Zhang, Y. Li, L. Shen, Y. Qi, L. Yang, J. Jena, P. Werner, K. Koepernik, S. Parkin, Y. Chen, C. Felser, B. A. Bernevig, Z. Wang,
A charge-density-wave topological semimetal,
Nat. Phys. (2021) (arXiv)