Disentangling the Competing Mechanisms of Light-Induced Anomalous Hall Conductivity in Three-Dimensional Dirac Semimetal
Yuta Murotani, Natsuki Kanda, Tomohiro Fujimoto, Takuya Matsuda, Manik Goyal, Jun Yoshinobu, Yohei Kobayashi, Takashi Oka, Susanne Stemmer, Ryusuke Matsunaga
Abstract
We experimentally elucidate the origin of the anomalous Hall conductivity in a three-dimensional Dirac semimetal, ${\mathrm{Cd}}_{3}{\mathrm{As}}_{2}$, driven by circularly polarized light. Using time-resolved terahertz Faraday rotation spectroscopy, we determine the transient Hall conductivity spectrum with special attention to its sign. Our results clearly show the dominance of direct photocurrent generation assisted by the terahertz electric field. The contribution from the Floquet-Weyl nodes is found to be minor when the driving light is in resonance with interband transitions. We develop a generally applicable classification of microscopic mechanisms of light-induced anomalous Hall conductivity.