A spin-glass model with random couplings
A spin-glass model is studied, which is similar to the one treated by the authors, \textit{V. Glaser} and \textit{A. Martin}, A spin glass with random couplings. J. Stat. Phys. 36, 89-106 (1984). The lattice and the type of the interaction are the same, the models differ in the assumption on the distribution of the interaction. In the present paper the random couplings are independent identically distributed, whereas in the other one certain couplings coincide. This causes frustration in the present case. The main topic of the paper is the behaviour of the effective random couplings under a change of scale, which leads to a renormalization group approach. The low and high temperature behaviour are studied. The existence of a critical fixed point and of a transition of the Edward-Anderson parameter is shown. The authors emphasize that their results can be viewed as an example of non-trivial behaviour of non-independent, but not strongly coupled random variables.
scientific article; zbMATH DE number 3881647