Ballistic transport of (001) GaAs two-dimensional holes and hole-flux composite fermions through a lateral strain-induced superlattice

The addition of a unidirectional superlattice on the surface of high-mobility two-dimensional carrier systems leads to a potential modulation signaled by the observation of magnetoresistance commensurability oscillations. We present measurements in high-mobility, two-dimensional (001) GaAs systems patterned with strain-induced surface superlattices of periodicity 100 to 250 nm. The data exhibit pronounced commensurability oscillations of holes near zero magnetic field and of hole-flux composite fermions near filling factor v = 1/2, allowing us to probe the Fermi contours of these quasi-particles.