1. Department of Physics and Astronomy, University of California, Irvine, California 92697, United States
2. School of Mechanical Engineering and Jiangsu Key Laboratory for Design and Manufacture of Micro-Nano Biomedical Instruments, Southeast University, Nanjing 211189, China
3. Department of Chemistry, University of California, Irvine, California 92697, United States
4. Soft Condensed Matter, Debye Institute for NanoMaterials Science, Utrecht University, Princetonplein 1, 3584 CC Utrecht, The Netherlands
5. Department of Physics, Nankai University, Tianjin 300457, China
6. Department of Physics, Clarkson University, Potsdam New York 13699, United States
7. Department of Materials Science, GSI Helmholtz Center for Heavy Ion Research, Darmstadt 64291, Germany
8. Department of Biomedical Engineering, University of California, Irvine, California 92697, United States