Mw. Beims et Jac. Gallas, Integrals of motion and quantum operators for hydrogenic atoms in externalfields - art. no. 043410, PHYS REV A, 6204(4), 2000, pp. 3410
We report five cases of integrability for a hydrogenic atom under three sta
tic external fields: a magnetic field, an electric field, and a van der Waa
ls interaction. Exact integrals of motion and corresponding quantum operato
rs are obtained explicitly for each case. Integrals of motion (quantum oper
ators) can be expressed as components of a suitably generalized Runge-Lenz
vector (operator). Quadratic quantum operators are found to have the amazin
g property of requiring a nonclassical extra term proportional to (h) over
bar(2). The structuring of the classical phase space is investigated numeri
cally via Poincare surfaces of section and corroborates the analytical resu
lts.