Two-dimensional defect solitons in parity-time-symmetric periodic optical lattices Hong Wang, Shuang Shi, Wei He, Xing Zhu and Yingji He Eur. Phys. J. D, 68 10 (2014) 322 Published online: 28 October 2014 DOI: 10.1140/epjd/e2014-40513-1