Violent Events in Superfluid 3Helium and a Collective Model of Glasses

点击翻译按钮获取中文摘要

A study will be made of various types of phenomenon in superfluid 3helium which involve violent departures from equilibrium and/or strongly nonlinear dissipation. Examples of such problems are the way in which textures and bulk magnetization follow the moving A-B interface, dissipation by moving singular vortices, the Josephson effect in both mass and spin supercurrent flow, and the dynamics of a wire vibrating in superfluid 3helium-B at very low tempertures. A conscious attempt will be made to develop intermediate-level, phenomenological concepts for this type of problem, rather than relying on existing microscopic technology. Also an attempt will be made to develop into a quantitative theory a collective scenario for the thermal and acoustic properties of glasses. The scenario is based on the idea that the underlying principle of the striking universality in glassy properties is to be sought in the phonon-mediated interactions of the stress variables of large subvolumes. It is hoped that such a model will replace the currently established "tunnelling two- level system" model at low tempertures, and in addition explain much of the intermediate- and high-temperature behavior, such as the plateau in the thermal conductivity, which is believed to correspond to the point at which the retarded nature of the phonon-induced interaction begins to play a substantial role.