1. Department of Physics, The Ohio State University, 191 W. Woodruff Avenue, Columbus, Ohio 43210, USA
2. Department of Electrical and Computer Engineering, The Ohio State University, 2015 Neil Avenue, Columbus, Ohio 43210, USA
3. Department of Chemistry and Biochemistry, The Ohio State University, 151 W. Woodruff Avenue, Columbus, Ohio 43210, USA
4. Department of Materials Science and Engineering, The Ohio State University, 2041 M. College Rd., Columbus, Ohio 43210, USA
5. Center for Electron Microscopy and Analysis, 1305 Kinnear Rd., Suite 100, Columbus, Ohio 43212, USA