Commensurability effects in lateral surface-doped superlattices

We fabricate density-modulated two-dimensional electron systems by shallow compensation doping the donor layer of a modulation-doped heterostructure. Zinc acceptor atoms are diffused from the sample surface which is heated by a focused laser beam. Low-temperature magnetotransport experiments provide evidence that high-quality lateral surface superlattices can be fabricated . In weak periodic one-dimensional potentials, commensurability oscillation s are recovered, whereas in strong periodic two-dimensional potentials the semiclassically expected antidot resistance resonances are found to dominat e the low-field transport. Additionally, the homogeneity of the laser-induc ed doping is confirmed by magnetic focusing experiments. (C) 2001 American Institute of Physics.