1. Department of Physics, Stanford University, Stanford, California 94305, USA
2. Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
3. Department of Materials Science and Engineering, Stanford University, Stanford, California 94305, USA
4. Institut für Experimentalphysik, Universität Duisburg-Essen, Duisburg, Germany
5. European Synchrotron Radiation Facility, 38043 Grenoble Cedex, France
6. Solid State Physics Division, Johannes Kepler University, 4040 Linz, Austria
7. Linear Coherent Light Source, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA
8. Stanford Synchrotron Radiation Laboratory, SLAC National Accelerator Laboratory, Menlo Park, California 94025, USA