2015/05/31 by R. Y. Chen, S. J. Zhang, J. A. Schneeloch +4 · 1 citation
Physics and Astronomy · #cond-mat.mtrl-sci
paper · pdf · doi:10.1103/physrevb.92.075107
published as Phys. Rev. B 92, 075107 (2015) · 5 pages, 4 figures
arxiv created 2015/08/06 · arxiv updated 2015/08/12
Three dimensional (3D) topological Dirac materials are under intensive study recently. The layered compound ZrTe5 has been suggested to be one of them by transport and ARPES experiments. Here, we perform infrared reflectivity measurement to investigate the underlying physics of this material. The derived optical conductivity exhibits linear increasing with frequency below normal interband transitions, which provides the first optical spectroscopic proof of a 3D Dirac semimetal. Apart from that, the plasma edge shifts dramatically to lower energy upon temperature cooling, which might be associated with the consequence of lattice parameter shrinking. In addition, an extremely sharp peak shows up in the frequency dependent optical conductivity, indicating the presence of a Van Hove singularity in the joint density of state.