1. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, P. O. Box 800‐204, Shanghai 201800 (China)
2. Center for Bioengineering and Biotechnology, China University of Petroleum (Huadong), Changjiang West Road 66, Qingdao 266580 (China)
3. Institute of Materials Research and Engineering, Singapore 117602 (Republic of Singapore)
4. Physics Department, National University of Singapore, Singapore 117542 (Republic of Singapore)
5. College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China)
6. Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101 (China)
7. IBM Thomas J. Watson Research Center, New York, NY 10598 (USA)