[1] Natl Cent Univ, Dept Phys, Inst Biophys, Chungli 320, Taiwan
[2] Natl Cent Univ, Ctr Complex Syst, Chungli 320, Taiwan
[3] Acad Sinica, Inst Phys, Taipei 115, Taiwan
[4] Chinese Acad Sci, Inst Phys, Beijing Natl Lab Condensed Matter Phys, Beijing 100190, Peoples R China