Circular dichroism in the angle-resolved photoemission spectra of the charge density wave Weyl semimetal (TaSe₄)₂I

(TaSe₄)₂I is a Weyl semimetal candidate that undergoes a charge density wave (CDW) transition on its quasi-one-dimensional lattice. This makes it an ideal system to study the interplay between topological effects and strong correlations. In particular, the onset of CDW order links two Weyl nodes near the Fermi surface to open up a gap leading to axion electrodynamics. In this work, we explore the band structure of (TaSe₄)₂I in the proximity of Weyl nodes with high momentum resolution laser-based angle-resolved photoemission (ARPES). Our results show strong circular dichroism in the measured ARPES spectra both above and below the CDW transition temperature (~260 K). We will discuss the implications of our results based on the predicted spin/orbital texture and effects of CDW on the electronic band structure of (TaSe₄)₂I near the Weyl nodes.