Quantum spin liquid in interacting Kane-Mele model with staggered on-site potential Yan-Hua Zong, Jing He and Su-Peng Kou Eur. Phys. J. B, 86 1 (2013) 28 Published online: 28 January 2013 DOI: 10.1140/epjb/e2012-30514-3