[1] Bender C M,Boettcher S. Real spectra in non-Hermitian Hamiltonians having PT symmetry[J]. Phys. Rev. Lett.,1998,80: 5243-5246.
[2] Guo A,Salamo G J,Duchesne D,et al. Observation of PT-symmetry breaking in complex optical potentials[J]. Phys. Rev. Lett.,2009,103: 093902.
[3] Rueter C E,Makris K G,El-Ganainy R,et al. Observation of parity-time symmetry in optics[J]. Nature Phys.,2010,6: 192-195.
[4] Musslimani Z H,Makris K G,El-Ganainy R,et al. Optical solitons in PT periodic potentials[J]. Phys. Rev. Lett.,2008,100: 030402.
[5] Makris K G,El-Ganainy R,Christodoulides D N,et al. Beam dynamics in PT-symmetric optical lattices[J]. Phys. Rev. Lett.,2008,100: 103904.
[6] Makris K G,El-Ganainy R,Christodoulides D N,et al. PT-symmetric periodic optical potentials[J]. Int. J. Theor. Phys.,2011,50: 1019-1041.
[7] Wang H,Wang J. Defect solitons in parity-time periodic potentials[J]. Opt. Expr.,2011,19: 4030-4035.
[8] He Y J,Zhu X,Mihalache D,et al. Lattice solitons in PT-symmetric mixed linear-nonlinear optical lattices[J]. Phys. Rev. A,2012,85: 013831.
[9] Zhu X,Wang H,Zheng L X,et al. Gap solitons in parity-time complex periodic optical lattices with the real part of superlattices[J]. Opt. Lett.,2011,36: 2680-2682.
[10] Nixon S,Ge L,Yang J. Stability analysis for solitons in PT-symmetric optical lattices[J]. Phys. Rev. A,2012,85: 023822.
[11] Li C Y,et al. Multi-stable solitons in PT-symmetric optical lattices[J]. Opt. Expr.,2012,20: 16823-16831.
[12] Li C Y,Huang C M,Liu H D,et al. Multipeaked gap solitons in PT-symmetric optical lattices[J]. Opt. Lett.,2012,37: 4543-4545.
[13] Zhu X,Wang H,Li H G,et al. Two-dimensional multipeak gap solitons supported by parity-time-symmetric periodic potentials[J]. Opt. Lett.,2013,38: 2723-2725.
[14] Zhu X,Li H G,Wang H,et al. Nonlocal multihump solitons in parity-time symmetric periodic potentials[J]. J. Opt. Soc. Am. B,2013,30: 1987-1995.
[15] Hu S M,Ma X K,Lu D Q,et al. Solitons supported by complex PT-symmetric Gaussian potentials[J]. Phys. Rev. A,2012,85: 043826.
[16] Li H G,Jiang X J,Zhu X,et al. Nonlocal solitons in dual-periodic PT-symmetric optical lattices[J]. Phys. Rev. A,2012,86: 023840.
[17] Lin Y Y,Jisha C P,Jeng C J,et al. Gap solitons in optical lattices embedded into nonlocal media[J]. Phys. Rev. A,2010,81: 063803.
[18] Nixon S,Ge L,Yang J. Stability analysis for soliton in PT-symmetric optical lattices[J]. Phys. Rev. A,2012,85: 023822.
[19] Kivshar Y S. Dark solitons in nonlinear optics[J]. IEEE J. Quantum Electron.,1993,29: 250-264.
[20] Kartashov Y V,Torner L. Gray spatial solitons in nonlocal nonlinear media[J]. Opt. Lett.,2007,32: 946-948.
[21] Louis P J Y,Ostrovskaya E A,Kivshar Y S. Matter-wave dark solitons in optical lattices[J]. J. Opt. B: Quantum Semiclass. Opt.,2004,6: S309.
[22] Johansson M,Kivshar Y S. Discreteness-induced oscillatory instabilities of dark solitons[J]. Phys. Rev. Lett.,1999,82: 85.
[23] Kivshar Y S,Luther-Davies B B. Dark optical solitons: Physics and applications[J]. Phys. Rep.,1998,298: 81.
[24] Ablowitz M J,Musslimani Z H. Spectral renormalization method for computing self-localized solutions to nonlinear systems[J]. Opt. Lett.,2005,30: 2140-2142.
[25] Fang L M,Gao J,Shi Z W,et al. Nonlocal defect solitons in parity-time-symmetric superlattices with defocusing nonlinearity[J]. Eur. Phys. J. D,2014,68: 298.
[26] Wang H,He W,Zheng L X,et al. Defect gap solitons in real linear periodic optical lattices with parity-timesymmetric nonlinear potentials[J]. J. Phys. B: At. Mol. Opt. Phys.,2012,45:245401.