Weakly (and not so weakly) bound states of a relativistic particle in one dimension

AMORE, PAOLO; JIMÉNEZ, ENRIQUE; FERNÁNDEZ, FRANCISCO M.

PHYSICS LETTERS A

ELSEVIER SCIENCE BV

Año: 2018 vol. 382 p. 2097 - 2102

0375-9601

We present the first exact calculation of the energy of the bound state of a one dimensional Dirac massive particle in weak short-range arbitrary potentials, using perturbation theory to fourth order (the analogous result for two dimensional systems with confinement along one direction and arbitrary mass is also calculated to second order). We show that the non-perturbative extension obtained using Padé approximants can provide remarkably good approximations even for deep wells, in certain range of physical parameters. As an example, we discuss the case of two gaussian wells, comparing numerical and analytical results, predicted by our formulas.