1. Unité Mixte de Physique, CNRS, Thales, Univ. Paris-Sud, Université Paris-Saclay, 91767, Palaiseau, France
2. Samsung Electronics, Semiconductor R&D Center (Grandis), San Jose, California 95134, USA
3. Moscow Institute of Physics and Technology, State University, Moscow 141700, Russia
4. Department of Electrical and Computer Engineering, University of California at San Diego, La Jolla, California 92093-0407, USA