Effect of elastic deformations on the multicritical behavior of disordered systems

A field-theoretical description of the behavior of disordered, elastically isotropic, compressible systems characterized by two order parameters at the bicritical and tetracritical points is presented. The description is performed in the two-loop approximation in three dimensions with the use of the Padé–Borel summation technique. The renormalization group equations are analyzed, and the fixed points corresponding to different types of multicritical behavior are determined. It is shown that the effect of elastic deformations causes a change in the regime of the tetracritical behavior of disordered systems because of the interaction of the order parameters through the deformation field.