- 1Technological Innovation Engineering, University Autonomous “Benito Juarez” of Oaxaca, Oaxaca 68120, Mexico
- 2Institute of Physics, Polish Academy of Sciences, Warsaw 02-668, Poland
- 3Instituto de Física, Benemérita Universidad Autónoma de Puebla, Apdo. Postal J-48, Puebla, Pue. 72570, Mexico
- 4Galkin Donetsk Institute for Physics and Engineering, NAS, Kyiv 03680, Ukraine
a)Electronic mail: cromeros@ifuap.buap.mx