  We study transport of indirect excitons in GaAs/AlGaAs coupled quantum wells
in linear lattices created by laterally modulated gate voltage. The
localization-delocalization transition (LDT) for transport across the lattice
was observed with reducing lattice amplitude or increasing exciton density. The
exciton interaction energy at the transition is close to the lattice amplitude.
These results are consistent with the model, which attributes the LDT to the
interaction-induced percolation of the exciton gas through the external
potential. We also discuss applications of the lattice potentials for
estimating the strength of disorder and exciton interaction.
