  We perform molecular dynamics simulations to investigate the effect of a
glass preparation on its yielding transition under oscillatory shear. We use
swap Monte Carlo to investigate a broad range of glass stabilities from poorly
annealed to highly stable systems. We observe a qualitative change in the
nature of yielding, which evolves from ductile to brittle as glass stability
increases. Our results disentangle the relative role of mechanical and thermal
annealing on the mechanical properties of amorphous solids, which is relevant
for various experimental situations from the rheology of soft materials to
fatigue failure in metallic glasses.
