1. Max Planck Research Department for Structural Dynamics, University of Hamburg–Centre for Free Electron Laser Science–Hamburg, Germany.
2. Department of Physics, Clarendon Laboratory, University of Oxford, Oxford, UK.
3. Department of Advanced Materials Science, University of Tokyo, Tokyo, Japan.
4. IKEN Advanced Science Institute, Hirosawa 2-1, Wako 351-0198, Japan.