  The dynamical axion field is a new state of quantum matter where the
magnetoelectric response couples strongly to its low-energy magnetic
fluctuations. It is fundamentally different from an axion insulator with a
static quantized magnetoelectric response. The dynamical axion field exhibits
many exotic phenomena such as axionic polariton and axion instability. However,
these effects have not been experimentally confirmed due to the lack of proper
topological magnetic materials. Here by combining analytic models and
first-principles calculations, we predict a series of van der Waal layered
Mn$_2$Bi$_2$Te$_5$-related topological antiferromagnetic materials could host
the long-sought dynamical axion field with a topological origin. We also show a
large dynamical axion field can be achieved in antiferromagnetic insulating
states close to the topological phase transition. We further propose the
optical and transport experiments to detect such a dynamical axion field. Our
results could directly aid and facilitate the search for topological-origin
large dynamical axion field in realistic materials.
