1. Department of Physics, Michigan Technological University, Houghton, Michigan 49931, United States
2. The Ames Laboratory, U.S. Department of Energy, Iowa State University, Ames, Iowa 50011, United States
3. Electrical and Computer Engineering Department, Iowa State University, Ames, Iowa 50011, United States
4. Henes Center for Quantum Phenomena, Michigan Technological University, Houghton, Michigan 49931, United States