1. Department of Physics, Colorado School of Mines, Golden, Colorado 80401, United States
2. National Renewable Energy Laboratory, Golden, Colorado 80401, United States
3. Department of Mechanical Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
4. Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, United States
5. Department of Electrical Engineering, University of Kentucky, Lexington, Kentucky 40506, United States
6. Michigan State University, Lansing, Michigan 48823, United States
7. Department of Physics, University of Washington, Seattle, Washington 98195, United States
8. Department of Metallurgical and Materials Engineering, Colorado School of Mines, Golden, Colorado 80401, United States
9. SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
10. Department of Mechanical Engineering, Stanford University, Stanford, California 94305, United States