Gauge Field Theory of Structural Transitions

From the viewpoint of gauge field theory, we have constructed the Lagrangian function of perfect crystal－the Lagrangian function of phonon field. Because of the break of symmetry of phonon field under the local group G=SO(3) we could introduce the gauge field of defects. With the aid of the spontaneous symmetry break of vacuum state and gauge field theory of defects, this paper presents the formulae of transition temperature c, jump quantity of Cv at transition Cv and order parameter i respectively. From these formulae, we can easily show the effect of defect on structural transition. Therefore, defect has been naturally introduced into the study of structural transition, and the mechanism of structural transition has also been discussed. Finally, we determined the coupled constant g of gauge field theory of defects.