Temperature dependent conductivity in magnetic Weyl semimetal Co3Sn2S2with terahertz spectroscopy

The recently discovered Weyl semimetal, Co3Sn2S2, is attractive for its intrinsic ferromagnetic behavior below Tc ~ 175 K with almost full spin polarization, i.e. half-metallicity. Previous studies^1,2 report evidence of a highly tunable, large anomalous Hall effect (AHE) with change in temperature. We utilize spectroscopic methods in the terahertz range to measure the optical conductivity in a single crystal Co3Sn2S2within the 8 K to 290 K temperature range. We observe a clear downward shift in the reflectance of the crystal with increasing temperatures near the ferromagnetic transition and a similar trend for low temperatures. We will discuss these measurements in the context of the Anomalous Hall conductivity that varies with shifts in Weyl node position.

¹ R. Yang, T. Zhang, L. Zhou, Y. Dai, Z. Liao, H. Weng, and X. Qiu, ArXiv:1908.03895 [Cond-Mat] (2019).
² X. Chen, M. Wang, C. Gu, S. Wang, Y. Zhou, C. An, Y. Zhou, B. Zhang, C. Chen, Y. Yuan, M. Qi, L. Zhang, H. Zhou, J. Zhou, Y. Yao, and Z. Yang, ArXiv:1909.09382 [Cond-Mat] (2019).