Bragg solitons in nonlinear PT-symmetric periodic potentials
  It is shown that slow Bragg soliton solutions are possible in nonlinear complex parity-time (PT) symmetric periodic structures. Analysis indicates that the PT-symmetric component of the periodic optical refractive index can modify the grating band structure and hence the effective coupling between the forward and backward waves. Starting from a classical modified massive Thirring model, solitary wave solutions are obtained in closed form. The basic properties of these slow solitary waves and their dependence on their respective PT-symmetric gain/loss profile are then explored via numerical simulations. 
Mohammad-Ali Miri, Alejandro B. Aceves, Tsampikos Kottos, Vassilios   Kovanis, and Demetrios N. Christodoulides
physics.optics math-ph math.MP nlin.SI quant-ph