1. Department of Electrical and Computer Engineering, Princeton University, Princeton, New Jersey 08544, United States
2. Department of Chemistry, Princeton University, Princeton, New Jersey 08544, United States
3. School of Science, RMIT University, Melbourne, Victoria 3000, Australia
4. ARC Centre of Excellence for Nanoscale BioPhotonics, School of Science, RMIT University, Melbourne, Victoria 3001, Australia
5. RMIT Microscopy and Microanalysis Facility, RMIT University, Melbourne, Victoria 3001, Australia
6. Element Six, Harwell OX11 0QR, United Kingdom
7. Wigner Research Centre for Physics, P.O. Box 49, 1525 Budapest, Hungary
8. Department of Atomic Physics, Institute of Physics, Budapest University of Technology and Economics, Müegyetem rakpart 3, 1111 Budapest, Hungary
9. Hyperion Materials & Technologies, 6325 Huntley Road, Columbus, Ohio 43229, United States