2011/07/31 by Sumei Hu, Xuekai Ma, Daquan Lu +2 · 1 citation
Physics and Astronomy · #physics.optics #nlin.PS
paper · pdf · doi:10.1103/physreva.85.043826
published as Phys. Rev. A 85, 043826 (2012) · 7 pages, 11 Figures, Accepted by Phy.Rev.A
arxiv created 2012/04/15 · arxiv updated 2012/04/19
The existence and stability of defect solitons in parity-time (PT) symmetric optical lattices with nonlocal nonlinearity are reported. It is found that nonlocality can expand the stability region of defect solitons. For positive or zero defects, fundamental and dipole solitons can exist stably in the semi-infinite gap and the first gap, respectively. For negative defects, fundamental solitons can be stable in both the semi-infinite gap and the first gap, whereas dipole solitons are unstable in the first gap. There exist a maximum degree of nonlocal nonlinearity, above which the fundamental solitons in the semi-infinite gap and the dipole solitons in the first gap do not exist for negative defects. The influence of the imaginary part of the PT-symmetric potentials on soliton stability is given. When the modulation depth of the PT-symmetric lattices is small, defect solitons can be stable for positive and zero defects, even if the PT-symmetric potential is above the phase transition point.