Mid Infrared Magneto-optical conductivity of RAlGe (R = La, Ce, Pr) Weyl semimetals

Magnetic Weyl semimetals RAlGe (R = La, Ce, Pr) show a rich topological behavior of Weyl fermions in their low-energy band structures. Here, we examine the fundamental characteristics of magneto-optical conductivity to obtain a deeper understanding of the Weyl nodes within RAlGe Weyl semimetals. We employ a conventional reflection measurement method alongside Kramers-Kronig analysis to investigate longitudinal optical conductivity. In addition, we use a custom-built broadband polarimetry technique to explore the preliminary infrared Hall conductivity. We report a strong mid infrared frequency dependence of magneto-optical conductivity with various temperatures and magnetic field in RAlGe Weyl semimetals. To further our study, we apply magnetic fields in-plane and out-of-plane. Our comparative study of optical conductivity across these three compounds has unveiled distinct infrared spectroscopic features unique to each type of Weyl semimetal. The initial insights derived from our study of infrared Hall conductivity pave the way for a deeper investigation into the intrinsic anomalous Hall conductivity arising from Weyl points.