Quantum nonlocality is an experimentally measurable quantum correlation indicated by theviolation of Bell inequality. Previous studies show that bipartite Bell inequality is notviolated in various translationally invariant spin models. In this paper, we studybipartite Bell inequality in an exactly soluble spin-1/2 XX chain displaying spin-Peierlstransition, where the system is in a uniform phase at high temperatures and in a dimerizedphase in low temperatures. The dimerization is induced by spin-phonon interactions in thesystem. We find that th...
