1. Department of Electrical Engineering
2. Korea University
3. Seoul 136-701
4. Republic of Korea
5. Rare Isotope Science Project
6. Institute for Basic Science
7. Daejeon 305-811, Republic of Korea
8. Quantum Functional Semiconductor Research Center
9. Dongguk University
10. Seoul 100-715, Republic of Korea
11. Department of Physics
12. Hanyang University
13. Seoul 133-791, Republic of Korea