The existence and stability of defect superlattice solitons in parity-time (PT) symmetric superlattice and simplelattice complex potentials are reported.Compared with defect simple-lattice solitons in similar potentials,the defect soliton in superlattice has a wider stable range than that in simple-lattice.The solitons’ power increases with increasing propagation constant.For the positive defect,the solitons are stable in the whole region where solitons exist in the semi-infinite gap.For the zero defect,the solitons are unstable at the edge of the band.For the negative defect,the solitons propagate with the shape of Y at low propagation constant and propagate stably at the large one.
The existence and stability of defect superlattice solitons in parity-time (PT) symmetric superlattice and simplelattice complex potentials are reported. Compared with defect simple-lattice solitons in similar potentials, the defect soliton in superlattice has a wider stable range than that in simple-lattice. The solitons' power increases with increasing propagation constant. For the positive defect, the solitons are stable in the whole region where solitons exist in the semi-infinite gap. For the zero defect, the solitons are unstable at the edge of the band. For the negative defect, the solitons propagate with the shape of Y at low propagation constant and propagate stably at the large one.