▎ 摘　　要

Graphene quantum dot with Maxwe l l fish eye potential ener g y profile is studied. A quasiclassical approximation is used given that potential energy is a slowly varying function of coordinates. Near the zero energ y the spectrum of electron macroscopically degenerates. A l l the electron trajectories are closed circles that are classified by angular momentum and an additional integral of motion. Provided the complete filling of the lower Dirac zone, a universal value for Ha l l conductivity is found .