En las fronteras de la Materia Condensada

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.