INTERACTING HOLES IN CUO CYCLIC CHAINS

The Kondo-reduced Emery model is investigated for cyclic CuO chains. W hen the spin-exchange coupling is zero, the model is exactly solvable in terms of spinless fermion operators. In the general case we find th at the ground state energy has an unconventional dependence on an exte rnal magnetic flux. This behaviour can be interpreted as due to an ind uced statistical flux. The strong-coupling behaviour can be explained in terms of compound particles, which allows some rigorous results in this limit.