1. Department of Electronics Engineering and Institute of Electronics National Chiao Tung University Hsinchu 300 Taiwan
2. Department of Chemical and Materials Engineering National Central University Jhongli 320 Taiwan
3. National Nano Device Laboratories Hsinchu 300 Taiwan
4. Department of Electrophysics National Chiao Tung University Hsinchu 300 Taiwan
5. Taiwan Consortium of Emergent Crystalline Materials, (TCECM) Ministry of Science and Technology Taipei 106 Taiwan
6. Department of Physics National Chung Hsing University Taichung 402 Taiwan