1. Department of Chemistry & Biochemistry, The Ohio State University, Columbus, Ohio 43210, United States
2. Department of Physics, The Ohio State University, Columbus, Ohio 43210, United States
3. Department of Materials Science and Engineering, The Ohio State University, Columbus, Ohio 43210, United States
4. Department of Physics, Duke University, Durham, North Carolina 27708, United States
5. Department of Mechanical & Aerospace Engineering, The Ohio State University, Columbus, Ohio 43210, United States