Nonsingular potentials from excited state factorization of a quantum system with position-dependent mass

The modified factorization technique of a quantum system characterized by a position-dependent mass Hamiltonian is presented. It has been shown that the singular superpotential defined in terms of a mass function and an excited state wavefunction of a given position-dependent mass Hamiltonian can be used to construct non-singular isospectral Hamiltonians. The method has been illustrated with the help of a few examples. (paper)