1. Department of Materials Science
and Engineering, University of California, Berkeley, California 94720, United States
2. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California
94720, United States
3. School
of Electronic Science and
Engineering, Nanjing University, Nanjing,
Jiangsu 210093, China
4. The
Molecular Foundry, Lawrence Berkeley National Laboratory, Berkeley, California
94720, United States
5. National
Center for Electron
Microscopy, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States
6. Department of Condensed Matter Physics
and Materials Science, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India
7. Department of Electrical Engineering
and Computer Science, University of California, Berkeley, California 94720, United States