Commensurability oscillations in the Hall resistance of unidirectional lateral superlattices

We have observed commensurability oscillations (CO) in the Hall resistance R-yx of a unidirectional lateral superlattice (ULSL). The CO, having small amplitudes (similar to 1 Omega) and being superposed on a roughly three orders of magnitude larger background, are obtained by directly detecting the difference in R-yx between the ULSL area and the adjacent unmodulated two-dimensional electron gas area and then extracting the odd part with respect to the magnetic field. The CO thus obtained are compared with a theoretical calculation and turn out to have the amplitude much smaller than the theoretical prediction. The implication of the smaller-than-predicted CO in R-yx on the thermoelectric power of ULSL is briefly discussed.