𝒫𝒯-symmetry-breaking induced suppression of tunneling in a driven non-Hermitian two-level system Xiao Lian, Honghua Zhong, Qiongtao Xie, Xiaoqing Zhou, Yunwen Wu and Wenhu Liao Eur. Phys. J. D, 68 7 (2014) 189 Published online: 24 July 2014 DOI: 10.1140/epjd/e2014-50188-1