1. Physik-Department E11, Technische Universität München, James-Franck-Strasse, D-85748 Garching, Germany
2. Center for Quantum Life Sciences and Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima 739-8526, Japan
3. Physical Sciences Division, Pacific Northwest National Laboratory, 902 Battelle Boulevard, P.O. Box 999, MS K1-83, Richland, Washington 99352, USA