1. Department of Physics and Astronomy, Stony Brook University, Stony Brook, New York 11794, USA
2. Department of Mechanical Engineering and Materials Science, Stony Brook University, Stony Brook, New York 11794, USA
3. Department of Mechanical Engineering and Materials Science, State University of New York at Binghamton, Binghamton, New York 13902, USA
4. Department of Physics, Columbia University, New York, New York 10027, USA
5. Department of Physics, Yale University, New Haven, Connecticut 06520, USA
6. Energy Sciences Institute, Yale University, West Haven, Connecticut 06516, USA