Analysis of quantum manifestations of chaos in general Rydberg atoms in strong magnetic fields

We present a method for calculating quantum spectra of arbitrary highly excited atoms in strong magnetic fields at fixed scaled energy {ε}=E/B2/3. Since classical dynamics depends exclusively on {ε}, this approach is most suited to analyzing the quantum manifestations of classical chaos. We find that modulations of the spectra associated with classical periodic orbits depend strongly on the quantum defect {μ}. In particular, the spectra at given {ε} are most (least) modulated for integer (half-integer) values of {μ}. We also find that the energy-level statistics tend more closely towards the Wigner (``chaotic'') limit for half-integer {μ}.