Measurement of Thermoelectric Power in Unidirectional Lateral Superlattices.

We have measured thermoelectric power in unidirectional lateral superlattices (ULSLs). The oscillations due to the Landau quantization in the longitudinal thermoelectric power Sxx exhibit marked amplitude modulation, analogous to but more pronounced than the amplitude modulation of the Shubnikov-de Haas oscillations in the resistivity ρxx. The semiclassical commensurability oscillations are not evident in Sxx, but are expected to be more apparent in the transverse component with the temperature gradient applied perpendicular to the principal axis of ULSLs, underlining the qualitative difference between the resistivity and the thermoelectric power in the way the anisotropy manifests itself. [ABSTRACT FROM AUTHOR]