1. Department of Electrical and Computer Engineering, University of California Los Angeles, Los Angeles, California 90095, United States
2. Department of Mechanical Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
3. NanoElectronic Imaging Inc., Los Angeles, California 90095, United States
4. School of Physics and Astronomy, Cardiff University, Cardiff, Wales CF24 3AA, U.K.
5. Electronics and Telecommunications Research Institute, Daejeon 34129, South Korea
6. Department of Physics, Ulsan National Institute of Science and Technology (UNIST), Ulsan 44919, South Korea
7. Department of Data Information and Physics, Kongju National University, Gongju 32588, South Korea
8. Department of Electrical Engineering, University of Texas at Arlington, Arlington, Texas 76019, United States