1. School of Applied and Engineering Physics, Cornell University , Ithaca, NY , USA
2. Singh Center for Nanotechnology, University of Pennsylvania , Philadelphia, PA , USA
3. Retired from Sandia National Laboratories , Albuquerque, NM , USA
4. EXpressLO LLC , Lehigh Acres, FL , USA
5. Kavli Institute for Nanoscale Science, Cornell University , Ithaca, NY , USA