Ladder operators for the BenDaniel-Duke Hamiltonians and their SUSY partners

Position-dependent mass systems can be described by a class of operators which include the BenDaniel-Duke Hamiltonians. The usual methods to solve this kind of problems are, in general, either numerical or those looking for a connection with constant mass problems. In this paper we impose the existence of first-order ladder operators to fix our initial system. Then, we perform the first- and second-order supersymmetric transformations to generate families of Hamiltonians whose eigenfunctions are known analytically for a given mass profile.