Dynamical localization: Hydrogen atoms in magnetic and microwave fields

We show that dynamical localization for excited hydrogen atoms in magnetic and microwave fields takes place at quite low microwave frequency (ω${\mathrm{n}}^3$≪1). Estimates of the localization length are given for different parameter regimes, showing that the quantum delocalization border drops significantly as compared to the case of zero magnetic field. This opens up broad possibilities for laboratory investigations.