Observation of momentum-dependent charge density wave gap in a layered antiferromagnet [Formula: see text].

Charge density wave (CDW) ordering has been an important topic of study for a long time owing to its connection with other exotic phases such as superconductivity and magnetism. The [Formula: see text] (R = rare-earth elements) family of materials provides a fertile ground to study the dynamics of CDW in van der Waals layered materials, and the presence of magnetism in these materials allows to explore the interplay among CDW and long range magnetic ordering. Here, we have carried out a high-resolution angle-resolved photoemission spectroscopy (ARPES) study of a CDW material [Formula: see text], which is antiferromagnetic below [Formula: see text], along with thermodynamic, electrical transport, magnetic, and Raman measurements.