1. Department of Electrophysics, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
2. Department of Electronic Engineering, National Formosa University, Yunlin 632, Taiwan
3. FAB 12B, Taiwan Semiconductor Manufacturing Company, Ltd., Hsinchu 300, Taiwan
4. Research Center for Applied Sciences, Academia Sinica, Taipei 115, Taiwan
5. Institute of Physics and Center for Emergent Functional Matter Science, National Yang Ming Chiao Tung University, Hsinchu 300, Taiwan
6. National Synchrotron Radiation Research Center, Hsinchu 300, Taiwan
7. Taiwan Consortium of Emergent Crystalline Materials (TCECM), National Science and Technology Council, Taipei 115, Taiwan
8. Department of Physics, University of Washington, Seattle, Washington 98195, United States