1. Applied Condensed-Matter Physics, Department of Physics and Astronomy, Faculty of Science, University of Potsdam, Karl-Liebknecht-Strasse 24-25, 14476 Potsdam-Golm, Germany
2. Department of Informatics, Informatics Center, Federal University of Paraíba, Rua dos Escoteiros, s/n Campus de Mangabeira João Pessoa-PB 58058-600, Brazil