[1] Chiba Univ, Grad Sch Engn, Chiba 2638522, Japan
[2] Acad Sinica, Inst Atom & Mol Sci, Taipei 10617, Taiwan
[3] Natl Taiwan Univ, Dept Phys, Taipei 10617, Taiwan
[4] Sungkyunkwan Univ, Sch Elect & Elect Engn, Suwon 16419, South Korea
[5] NIST, Gaithersburg, MD 20899 USA
[6] Natl Inst Mat Sci, Adv Mat Lab, 1-1 Namki, Tsukuba, Ibaraki 3050044, Japan