Bell inequality in an exactly soluble spin-1/2 XX chain displaying spin-Peierls transition Bai-Jun Chen, Zhao-Yu Sun, Hai-Lin Huang and Bo Wang Eur. Phys. J. B, 87 12 (2014) 282 Published online: 01 December 2014 DOI: 10.1140/epjb/e2014-50479-3