Affiliation: | (1) Departement of Physics “E.R. Caianiello”, University of Salerno, via S. Allende, 84081 Baronissi, Italy;(2) CNR-INFM 'SUPERMAT' Research Unit, via S. Allende, 84081 Baronissi, Italy;(3) Departement of Mathematics and Informatics, University of Salerno, via Ponte don Melillo, 84084 Fisciano, Italy |