Composition of Two Potentials
  Given two potentials V0 and V1 together with a certain nodeless solution {\phi}0 of V0, we form a composition of these two potentials. If V1 is exactly solvable, the composition is exactly solvable, too. By combining various solvable potentials in one-dimensional quantum mechanics, a huge variety of solvable compositions can be made. 
Khosrow Chadan, Reido Kobayashi, Ryu Sasaki
math-ph math.MP