The instability of long-period commensurate phases in the presence of quenched impurities

Abstract

Domain-wall arguments are used to study the stability of long-period commensurate phases in the presence of quenched impurities. It is found that in three dimensions phases with periodicity larger than a critical value l_c approximately 1/c, where c is the impurity concentration, are unstable. This results in disordered 'spin glass'-like phases. The effect can be studied experimentally by varying the impurity concentration in modulated systems.