Physical Review A
Rydberg atoms in weak magnetic fields
A. P. Kazantsev, V. L. Pokrovsky, János A. Bergou
Abstract
The quadratic Zeeman effect of Rydberg atoms is treated with the help of first-order perturbation theory and a special WKB approximation. The Bohr-Sommerfeld quantization leads to complete elliptic integrals. As a result we found that the spectrum is doubly degenerate if $\frac{{n}^{2}}{{m}^{2}>5}$, this part exhibiting a linear Stark effect in an additional weak electric field; the rest of the spectrum ($\frac{{n}^{2}}{{m}^{2}<5}$) is nondegenerate, exhibiting a quadratic Stark effect in an additional weak electric field.