1. Department of Materials Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
2. Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
3. Department of Physics & IRIS Adlershof, Humboldt-Universität zu Berlin, 12489 Berlin, Germany
4. Central European Institute of Technology, Brno University of Technology, 61200 Brno, Czech Republic
5. Diamond Light Source, Harwell Campus, Didcot OX11 0DE, United Kingdom
6. College of Letters and Science, Physical Sciences, UCLA, Los Angeles, California 90095, United States
7. Materials Science and Engineering Department, University of Washington, Seattle, Washington 98195, United States