Circular dichroism as a probe for topology in three-dimensional semimetals

Higher-pseudospin fermions, associated with multiple band-crossings in topological semimetals, are the condensed matter analogues of higher-spin fermions high-energy physics. In this paper, we demonstrate that analyzing response a circular drive is an effective way to detect topology lowest-energy Bloch band, as it can be connected frequency-dependent probe. The dichroic exhibits dichroism due differential excitation rates by left- and right-circular orientations time-periodic drive, induced on filled because geometrical properties bands. Our analytical approximation reveals quantized for isotropic systems, when frequency above critical value, thus correctly infers ground-state Chern number. We through explicit numerical computations considering three kinds semimetals pseudospin values 1/2, 1, 3/2, respectively, all having linear dispersions. Furthermore, investigate effects tilt anisotropy find although does not have any effect response, presence drastically hamper quantization. scheme provides important methodology designing future experiments band structures.