  Recent advances in submicrometer technology have made it possible to confine
the two-dimensional electron gas into high-mobility semi-conductor
heterostructures. Such structure with a lattice of electron-depleted circular
obstacles are called quantum antidot lattices, or quantum Lorentz gas systems.
By using the semiclassical scattering theory, we show that quantum interference
in finite-size open Lorentz gas systems is expected to reflect the difference
between normal and anomalous diffusions, i.e., L\'evy flights.
