  A simple intuitive picture of spin-Peierls antiferromagnets arises from
regarding the elementary excitations as S=1/2 solitons. In a strictly
one-dimensional system these excitations are assumed not to form bound-states
and to be repelled by impurities. Couplings to the three-dimensional lattice
are assumed to produce an effective confining potential which binds solitons to
antisolitons and to impurities, with the number of bound-states increasing as
the interchain coupling goes to 0. We investigate these various assumptions
numerically in a phononless model where spontaneous dimerization arises from
frustration and the interchain coupling is treated in mean field theory.
