The existance of truly extended states in non-crystalline structures is a remrakable occurrence in
one dimensional lattices. Certain kinds of correlation in the disorder are known to generate such
states. Also, if the system is quasi-crystalline extended states may appear at a restricted set of
energies. Since it is easier to embed one dimensional lattices in two dimensions, we discuss the
observable properties of such states for transport. Of special interest is a superlattice made of
magnetic stripes, since then the two dimensions are entangled by the magnetic field. We shall
discuss the length dependence of the conductance and show that at certain energies the value is
finite in the infinite-length limit, revealing that an extended state has been captured by the
transport process.
Work done in collaboration with Z. Zeng and J. Maze. Supported in part by Fondecyt 1020829 and
Cátedra Presidencial en Ciencia.
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