A novel percolation theory for high temperature superconductors

• Autor(a) principal: Mello,E.V.L. de
• Data de Publicação: 2002
• Outros Autores: Caixeiro,E.S., Gonzaléz,J.L.
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Brazilian Journal of Physics
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S0103-97332002000400007

We present a percolation theory for the high-Tc oxides pseudogap and Tc dependence on the hole level. The doping dependent inhomogeneous charge structure is modeled by a distribution which may represent the stripe morphology and yield a spatial distribution of local Tc(r). The temperature onset of spatial dependent superconducting gap is identified with the vanishing of the pseudogap temperature T*. The transition to a superconducting state corresponds to the percolation threshold among regions of different Tc. As a paradigm we use a Hubbard Hamiltonian with a mean field approximation to yield a doping and temperature dependent superconducting d-wave gap. We show here that this new approach reproduces the phase diagram, explains and gives new insights on several experimental features of high-Tc oxides.