1. Graduate School of Integrated Arts and Sciences, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8521
2. Frontier Research System, The Institute of Physical and Chemical Research (RIKEN), Wako, Saitama 351-0198
3. AdSM, Hiroshima University, Higashi-Hiroshima, Hiroshima 739-8530
4. Center for Theoretical Physics, Physics Department, CSCS, The University of Michigan, Ann Arbor, MI 48109-1040, U.S.A.
5. MILq Project, International Project Center for Integrated Research on Quantum Information and Life Science, Higashi-Hiroshima, Hiroshima 739-8530