Quantum Effect and Dimensional Crossover in Spin Fluctuations

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Recently, there has been tremendous development in the research field of the low dimensional quantum antiferromagnetism. Numbers of new experimental facts are presented, such as the quantum spin fluctuations in 1 dimensional (1D) and 2D spin systems, dimensional cross over and/or universality in the spin space and/or symmetry and so forth. These new waves owe to the rapid growth in the materials research and development which enables us the opportunity to make fine experiments by using the prototype such low D magnets. Otherwise, these important and fundamental issues are closed only in theoretical interests. In fact, a long tradition in this research field made Japan as the leading country in the low dimensional magnetism as well. Though we are at this position of the world front, we don't think it is enough to collaborate internationally or to have international opportunities to discuss with. It is our primary aim to send many young scientists to abroad who work hard and present fascinating results and also to have opportunities of collaborations with foreign scientists.First, we organized two sequential workshops at the time of the large scaled international conference on neutron scattering research. These two workshops were so successful that foreign guests participated to these workshops acknowledged very fine presentations by Japanese young participants and their active contributions. We also appreciate several new observations from collaborative experiments done at HMI and NIST which gave us neutron beams for this project, since Japanese neutron source of JRR3 has been turned off for a half year. These results include quantum spin fluctuations in 2D antiferromagnets and quantum spin glass transition in the cuprate (s=1/2) oxides.