Recent years have witnessed a steady progress towards blending two-dimensional quantum materials into

technology, with future applications often rooted in the electronic structure. Since crossings and inversions of

electronic bands with different orbital characters determine intrinsic quantum transport properties, knowledge

of the orbital character is essential. Here, we benchmark angle-resolved photoelectron emission spectroscopy

(ARPES) as a tool to experimentally derive orbital characters. For this purpose we study the valence electronic

structure of two technologically relevant quantum materials, graphene andWSe2, and focus on circular dichroism

that is believed to provide sensitivity to the orbital angular momentum. We analyze the contributions related to

angular atomic photoionization profiles, interatomic interference, and multiple scattering. Regimes in which

initial-state properties could be disentangled from the ARPES maps are critically discussed and the potential

of using circular dichroic ARPES as a tool to investigate the spin polarization of initial bands is explored. For

the purpose of generalization, results from two additional materials, GdMn6Sn6 and PtTe2, are presented in

addition. This research demonstrates rich complexity of the underlying physics of circular dichroic ARPES,

providing insights that will shape the interpretation of both past and future circular-dichroic ARPES studies.

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