1. Institute of Physics, Academia Sinica, Taipei 10617, Taiwan
2. Department of Physics, National Taiwan University, Taipei 10617, Taiwan
3. Nano Science and Technology Program, Taiwan International Graduate Program, Academia Sinica and National Taiwan University, Taipei 11529, Taiwan
4. Department of Physics, School of Basic and Applied Sciences, Central University of Tamil Nadu, Neelakudi, Thiruvarur, 610005 Tamil Nadu, India
5. Department of Physics, Sungkyunkwan University, Suwon 16419, Republic of Korea
6. Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan
7. Department of Electro Physics, National Yang Ming Chiao Tung University, Hsinchu 300093, Taiwan
8. School of Electronic and Information Engineering, Changshu Institute of Technology, Changshu 215500, China
9. Department of Applied Physics, Zhejiang University of Technology, Hangzhou 310023, China
10. Institute of Earth Sciences, Academia Sinica, Taipei 10617, Taiwan
11. Department of Physics (MMV), Banaras Hindu University, Varanasi 221005, Uttar Pradesh, India
12. Physics Division, National Center for Theoretical Sciences, Taipei 10617, Taiwan