  Parity symmetric photoemission spectra are ubiquitous in solid state
research, being prevalent in many highly active areas, such as unconventional
superconductors, nonmagnetic and antiferromagnetic topological insulators, and
weakly relativistic collinear magnets, among others. The direct observation of
parity-violating metallic Kramers degenerate bands has remained hitherto
experimentally elusive. Here we observe the antiferromagnetic parity violation
(APV) in the bandstructure of Mn$_2$Au thin films by using momentum microscopy
with sub-$mu$m spatial resolution, allowing momentum resolved photoemission on
single antiferromagnetic domains. The APV arises from breaking the P symmetry
of the underlying crystal structure by the collinear antiferromagnetism, while
preserving the joint space-time inverison PT -symmetry and in combination with
large spin-orbit coupling. In addition, our work also demonstrates a novel tool
to directly image the Neel vector direction by combining spatially resolved
momentum microscopy with ab-initio calculations.
