1. Purdue Quantum Center and Birck Nanotechnology Center, School of Electrical and Computer Engineering, Purdue University, West Lafayette, IN 47906, USA.
2. Department of Electrical and Computer Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
3. Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
4. Department of Physics, University of Alberta, Edmonton, Alberta T6G 2E1, Canada.