On equivalent-neighbour, random site models of disordered systems

Zeitschrift für Physik B Condensed Matter - Tập 63 - Trang 247-257 - 1986
J. Jedrzejewski1, A. Komoda1
1Institute of Theoretical Physics, University of Wrocław, Wrocław, Poland

Tóm tắt

Models of random systems whose Hamiltonian reads $$H_\Lambda = - \tfrac{1}{2}\sum\limits_{i,j \in \Lambda } {J_{ij} S_i S_j } $$ , where $$S_i = \pm 1, J_{ij} = \frac{1}{{\# \Lambda }}(J_0 + \bar \xi _i Q\bar \xi _j + \bar L(\bar \xi _i + \bar \xi _j ), \bar \xi _i = (\bar \xi _{i1} ,...,\bar \xi _{in} )$$ andξ iμ ,μ=1,...,n are independent, identically distributed random variables are discussed.J ij are assumed to be symmetric, with respect toJ 0, random variables and also symmetric functions of components of $$\bar \xi _i $$ . A question of dependence of a phase diagram on a probability distribution of $$\bar \xi _i $$ is addressed. A class of distributions and interactionsJ ij , which give rise to phase diagrams called typical is selected. Then a problem of obtaining typical phase diagrams, containing a certain region with an infinite number of pure phases, is studied.

Tài liệu tham khảo

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