1Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB, Canada
2Department of Micro-Nano Electronic, Shanghai Jiao Tong University, Shanghai, China
3School of Integrated Circuits, Tsinghua University, Beijing, China
4College of Electronic and Information Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing, China
5Department of Electrical and Computer Engineering, Northeastern University, Boston, MA, USA