1. Department of Materials Science and Engineering, University of Michigan, 2300 Hayward St., Ann Arbor, Michigan 48109-2136, United States
2. Leibniz-Institut für Kristallzüchtung (IKZ), Max-Born-Straße 2, 12489 Berlin, Germany
3. Department of Electrical Engineering and Computer Science, University of Michigan, 1301 Beal Ave., Ann Arbor, Michigan 48109-2122, United States