A class of exactly solvable models to illustrate supersymmetry and test approximation schemes in quantum mechanics

Charlotte Fabre (1) , David Guéry-Odelin (1)

1 Atomes Froids (LCAR)

We derive the analytical eigenvalues and eigenstates of a family of potentials wells with exponential form (FPWEF). We provide a brief summary of the supersymmetry formalism applied to quantum mechanics and illustrate it by producing from the FPWEF another class of exact solutions made of their isospectral partners. Interestingly, a subset of the supersymmetric partners provides a class of exactly solvable double well potentials. We use the exact solutions of the FPWEF to test the robustness and accuracy of different approximation schemes. We determine (i) the ground state through variational method applied to an approriate set of trial functions and (ii) the whole spectrum using three semiclassical quantization formula: the WKB, JWKB and its supersymmetric extension, the SWKB quantization formula. We comment on the importance of Maslov index and on the range of validity of these different semiclassical approaches.

Domaines: Physique Quantique [quant-ph]; Physique Générale [physics.gen-ph]

Charlotte Fabre, David Guéry-Odelin. A class of exactly solvable models to illustrate supersymmetry and test approximation schemes in quantum mechanics. American Journal of Physics, 2011, 79, pp.755. ⟨10.1119/1.3567002⟩. ⟨hal-00547118⟩