1. Department of Physics, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
2. Institute of Computational Comparative Medicine and Nanotechnology Innovation Center of Kansas State, Department of Anatomy and Physiology, Kansas State University, Manhattan, Kansas 66506, United States
3. Shenzhen Research Institute, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
4. Laboratoire International Associé Centre National de la Recherche Scientifique et University of Illinois at Urbana−Champaign, Unité Mixte de Recherche n°7019, Université de Lorraine, B.P. 70239, 54506 Vandœuvre-lès-Nancy cedex, France
5. Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana−Champaign, 405 North Mathews Avenue, Urbana, Illinois 61801, United States
6. Department of Physics, University of Illinois at Urbana−Champaign, 1110 West Green Street, Urbana, Illinois 61801, United States