  Using extensive Monte Carlo simulations we study numerically and analytically
a photogalvanic effect, or ratchet, of directed electron transport induced by a
microwave radiation on a semidisk Galton board of antidots in graphene. A
comparison between usual two-dimensional electron gas (2DEG) and electrons in
graphene shows that ratchet currents are comparable at very low temperatures.
However, a large mean free path in graphene should allow to have a strong
ratchet transport at room temperatures. Also in graphene the ratchet transport
emerges even for unpolarized radiation. These properties open promising
possibilities for room temperature graphene based sensitive photogalvanic
detectors of microwave and terahertz radiation.

Mesoscale and Nanoscale Physics;Chaotic Dynamics