Envelope of commensurability magnetoresistance oscillation in unidirectional lateral superlattices

The envelope of the commensurability magnetoresistance oscillation (Weiss oscillation) has been studied for lateral superlattices prepared from two-dimensional electron gas (2DEG) wafers with varying mobility μ and spacer-layer thickness dₛ. When the 2DEG has a high enough μ and a large enough dₛ, the envelope is well described by the formula given by Peeters and Vasilopoulos in a first-order perturbation theory [Phys. Rev. B 46, 4667 (1992).]. For smaller μ or dₛ, the oscillation diminishes faster than the formula at lower B. The damping can be accounted for by an additional factor of the form [π/(μWB)]/sinh[π/(μWB)]. The parameter μW is found to be proportional to the mean free path L of the 2DEG, and the coefficient of proportionality increases with dₛ. The magnitude of μW, as well as its dependence on dₛ and the electron areal density nₛ, is close to that of μQ, the mobility corresponding to the total scattering time.