1. Department of Physics, University of Maryland, College Park, Maryland 20742, USA
2. Quantum Technology Center, University of Maryland, College Park, Maryland 20742, USA
3. Department of Electrical and Computer Engineering, University of Maryland, College Park, Maryland 20742, USA
4. Center for Astrophysics, Harvard & Smithsonian, Cambridge, Massachusetts, 02138, USA
5. Department of Physics, Harvard University, Cambridge, Massachusetts 02138, USA
6. Center for Nanoscale Materials, Argonne National Laboratory, Lemont, Illinois 60439, USA
7. Sandia National Laboratories, Albuquerque, New Mexico, 87123, USA
8. Center for Molecular Engineering, Argonne National Laboratory, Lemont, Illinois 60439, USA
9. Materials Science Division, Argonne National Laboratory, Lemont, Illinois 60439, USA
10. Department of Physics and Astronomy, Johns Hopkins University, 3400 N. Charles St., Baltimore, Maryland 21218, USA
11. Department of Physics, Boston University, Boston, Massachusetts 02215, USA
12. Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215, USA
13. Photonics Center, Boston University, Boston, Massachusetts 02215, USA
14. Pritzker School of Molecular Engineering, University of Chicago, Chicago, Illinois 60637, USA