Electron transport through antidot superlattices in Si/Si0.7Ge0.3 heterostructures

Transport properties of electrons in antidot superlattices are studied in Si/Ge heterostructures. Lateral superlattices with periods between 830 and 500 nm were imposed upon high-mobility two-dimensional electron gases in Si/Si0.7Ge0.3 heterostructures by means of laser holography and reactive ion etching. Typical features known from GaAs/AlxGa1-xAs samples, such as low-field commensurability oscillations in the longitudinal resistivity xx, additional nonquantized Hall plateaus, and quenching of the Hall effect around B=0, are observed. From the position of the commensurability maxima in xx we conclude that the lateral potential is rather smooth.