1. Tianjin Key Laboratory of Brain Science and Neural Engineering Academy of Medical Engineering and Translational Medicine Tianjin University Tianjin 300072 China
2. Department of Physics and Tianjin Key Laboratory of Low Dimensional Materials Physics and Preparing Technology School of Science Tianjin University Tianjin 300354 China
3. Beijing Synchrotron Radiation Facility (BSRF) Institute of High Energy Physics (IHEP) Chinese Academy of Sciences (CAS) Beijing 100049 China
4. Department of Materials Science and Engineering Stanford University Stanford California 94305 USA
5. Tianjin Neurological Institute Department of Neurosurgery General Hospital Tianjin Medical University Tianjin 300041 China
6. School of Electronics and Information Technology and Medicine Sun Yat‐sen University Guangzhou 510060 China
7. Department of Biomedical Engineering College of Engineering Peking University Beijing 100871 China