Jump-defects in the nonlinear Schrodinger model and other   non-relativistic field theories
  Recent work on purely transmitting 'jump-defects' in the sine-Gordon model and other relativistic field theories is extended to non-relativistic models. In all the cases investigated the defect conditions are provided by 'frozen' Backlund transformations and it is also shown via a Lax pair argument how integrability will be preserved in the presence of this type of defect. Explicit examples of the scattering of solitons by defects are given, and bound states associated with 'jump-defects' in the nonlinear Schrodinger model are described. Although the nonlinear Schrodinger model provides the principal example, some results are also presented for the Korteweg de Vries and modified Korteweg de Vries equations. 
E. Corrigan and C. Zambon