1. School of Electrical Engineering and Computer Science, Kyungpook National University, 1370 Sankyuk-dong, Buk-gu, Daegu 702-701, Republic of Korea
2. BK21 Physics Program and Department of Physics, College of Natural Science, Chungbuk National University, Cheongju, Chungbuk 361-763, Republic of Korea
3. Laboratoire de Physique Quantique et Systèmes Dynamiques, Département de Physique, Faculté des Sciences, Université Ferhat Abbas de Sétif, Sétif 19000, Algeria