1. Department of Material Physics, Faculty of Engineering Science, Osaka University, Toyonaka, Osaka 560-8531
2. Department of Physics, Tokyo Metropolitan University, Hachioji, Tokyo 192-0397
3. Department of Physics, Tohoku University, Sendai 980-8578
4. Department of Physics, Hiroshima University, Higashi-Hiroshima 739-8526
5. Department of Mathematics and Physics, The National Defense Academy, Yokosuka 239-8686
6. Department of Material Science and Technology, Niigata University, Niigata 950-2181