1. Stanford Institute for Materials and Energy Sciences, Stanford University and SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
2. Linac Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
3. Naval Information Warfare Center Pacific, San Diego, California 92152, USA
4. Department of Physics, University of California—San Diego, La Jolla, California 92093, USA
5. Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
6. Department of Physics, University of Oregon, Eugene, Oregon 97401, USA
7. Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, California 94720, USA
8. SSRL, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
9. Physics Department, Materials Science & Engineering Initiative, UC Santa Cruz, Santa Cruz, California 95064, USA
10. Center for Memory and Recording Research, University of California—San Diego, La Jolla, California 92093, USA
11. Department of Electrical and Computer Engineering, University of California—San Diego, La Jolla, California 92093, USA