Anisotropic thermal and electrical transport of Weyl semimetal TaAs


We report on anisotropic electrical, thermal as well as thermoelectric properties of the prototypical Weyl semimetal TaAs. Compared to the normal metallic behavior along a axis, TaAs is more electrically resistive along c axis and exhibits a semiconductor-like resistivity upturn below [Formula: see text] K. In the same temperature range, the thermal conductivity along c axis shows a pronounced maximum of 183 [Formula: see text] characteristic of a crystalline solid, three times higher than that of a axis. The thermoelectric power, while exhibiting enhanced values around room temperature, becomes diminished in a substantial range of temperature ([Formula: see text] K) for both axes. Together with the enhanced Nernst signals, this hints at a dominating ambipolar diffusion as is frequently seen in a compensated semimetal. An in-depth investigation of the anisotropic transport quantities is expected to yield deep insights into the propagating Weyl fermions in TaAs.

J Phys Condens Matter.