Abstract

Darboux transformations are employed in construction and analysis of Dirac Hamiltonians with pseudoscalar potentials. By this method, we build a four-parameter class of reflectionless systems. Their potentials correspond to the composition of complex kinks, also known as twisted kinks, that play an important role in the 1 + 1 Gross-Neveu and Nambu-Jona-Lasinio field theories. The twisted kinks turn out to be multisolitonic solutions of the integrable Ablowitz-Kaup-Newell-Segur hierarchy. Consequently, all the spectral properties of the Dirac reflectionless systems are reflected in a nontrivial conserved quantity, which can be expressed in a simple way in terms of Darboux transformations. We show that the four-parameter pseudoscalar systems reduce to well-known models for specific choices of the parameters. An associated class of transparent nonrelativistic models described by a matrix Schrodinger Hamiltonian is studied and the rich algebraic structure of their integrals of motion is discussed.