Networking and Cooperative Dynamics in Complex Physical Systems (III)

Phase transition and critical phenomena in some complex physical systems of layer structure are examined from the viewpoint of networking and cooperative dynamics. There are included critical phenomena at the phase transitions of a Heisenberg-type antiferromagnet Cu (HCOO)_2. 2H_2O. 2CO(NH_2)_2 and of an organic superconductor κ-(BEDT-TTF)_2Cu(NCS)_2. The characteristic features are all concerned with highly developed short range order coming from the two-dimensional lattice structure and also with a remarkable effect of weak interlayer coupling near the critical point. Such characteristic critical phenomena of these systems suggest an occurrence of phase transitions associated with a symmetry breaking on chiral degree of freedom.