1. School of Electrical and Computer Engineering, College of Engineering, University of Tehran, Tehran 14395-515, Iran
2. Department of Physics, Shahid Rajaee Teacher Training University, 16875-163 Lavizan, Tehran, Iran
3. Department of Physics, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerpen, Belgium
4. School of Physics, The University of Sydney, New South Wales 2006, Australia
5. Super Computing Institute, University of Tehran, Tehran, Iran
6. Institute for Microelectronics, Technische Universität Wien, Gußhausstraße 27–29/E360, A-1040 Wien, Austria