Application of Berezinskii's Diagram Method to Bond Disordered System with the Dimerization and the Staggered Field

Abstract

Based on the Berezinskii's diagram method, the density of states (DOS) of a bond disordered system has been calculated in the presence of the dimerization and the staggered field. It is found that the DOS near the center of the band behaves anomalously and that it is indicated that this feature is the cause of the coexistence phase of antiferromagnetism (AF) and dimerization in the disordered quasi-one-dimensional spin-Peierls (SP) system CuGe_1-ySi_yO₃.