Macroscopic Collective Excitations Associated with Phase Changes
Koichiro Matsuno
A model is proposed of a dynamic associated with general phase changes. We regard a system exhibiting various collective phenomena near the phase change point, where a macroscopic variable X approaches a transition point Xc, as a strongly interacting many-cluster system. The cluster means that of unstable phase locally appearing as fluctuations in the overwhelmingly large area of stable phase. The variable X is temperature in many cases. The present hypothesis enables us to find a form of the propagator of the cluster-excitation, whose linewidth is shown to be a homogeneous function of the wave number and the characteristic length diverging as |X-Xc|2/3 for X →;Xc except for Xc = absolute zero on the temperature axis. A hydrodynamics in the interacting many-cluster system yields an energy density wave which leads to the thermal conductivity diverging as |X-Xc|-1/3 for X →;Xc. When the transition point is absolute zero on the temperature axis T, the temperature dependence of the characteristic length, the specific heat and the thermal conductivity is of the form T-1/3, T and T7/3, respectively, for T →0.
Progress of Theoretical Physics•Sep 1, 1973•0 citations