1. Communications Technology Laboratory, National Institute of Standards and Technology 1 , Boulder, Colorado 80305, USA
2. PASTEUR, Department of Chemistry, École Normale Supérieure, PSL University, Sorbonne Université, CNRS 2 , 75005 Paris, France
3. Material Measurement Laboratory, National Institute of Standards and Technology 3 , Gaithersburg, Maryland 20899, USA
4. Materials Science and Engineering, Rensselaer Polytechnic Institute 4 , Troy, New York 12180, USA