Nonsingular potentials from excited state factorization of a quantum   system with position dependent mass
  The modified factorization technique of a quantum system characterized by position-dependent mass Hamiltonian is presented. It has been shown that the singular superpotential defined in terms of a mass function and a excited state wave function 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. 
Bikashkali Midya (Indian Statistical Institute)
quant-ph math-ph math.MP