Discovery of a Three-Dimensional Topological Dirac Semimetal, Na3Bi
Author List: Z.K. Liu, B. Zhou, Y. Zhang, Z.J. Wang, H.M. Weng, D. Prabhakaran, S-K. Mo, Z.X. Shen, Z. Fang, X. Dai, Z. Hussain, Y.L. Chen
Journal Reference: Science, Vol. 343 no. 6173 pp. 864-867, DOI: 10.1126/science.1245085, published 21 February 2014
Link to PDF: https://www.sciencemag.org/content/343/6173/864.full.pdf
Online Journal Link: http://www.sciencemag.org/
Discoveries of materials with exciting electronic properties have propelled condensed matter physics over the past decade. Two of the best-known examples, graphene and topological insulators, have something in common: a linear energy-momentum relationship—the Dirac dispersion—in their two-dimensional (2D) electronic states. Topological insulators also have a more mundane aspect of their electronic structure, characterized by a band gap. Another class of materials, topological Dirac semimetals, has been proposed that has a linear dispersion along all three momentum directions—a bulk Dirac cone; these materials are predicted to have intriguing electronic properties and to be related to other exotic states through quantum phase transitions. Liu et al. (p. 864, published online 16 January) detected such a state in the compound Na3Bi by using photoemission spectroscopy.