Magnetoconductivity in a mesoscopic antidot array.

We describe studies of magnetotransport in antidot arrays formed by focused ion-beam implantation. This shows the dominant role played by interconnects between dotlike reservoirs. Two separate Shubnikov-de Haas periodicities are observed at high and low fields, which allow separate measurements of the depth of the reservoirs and the interconnects. A large negative magnetoresistance is observed at low fields, which is interpreted as being due to the formation of propagating edge states as the field increases