MAGNETIC-PROPERTIES OF THE HUBBARD-MODEL WITH STRONG INTERACTION

The problem of the ground state multiplicity of the Hubbard model with infinite interaction is considered for the systems consisting of weakly bound segments of length n (an n-chain model). It is shown that the total spin S of the ground state grows from 0 to S(max) with an increase of electron densities S. For two chain model the critical value S(c) is found, above which the ground state is ferromagnetic. For n chain model with n > 2 a "cascade" of the transitions with alteration of total spin takes place.