Observation of dynamical localization in a rough microwave cavity

We measure the angular momentum content of modes in a flat, near-circular m icrowave cavity with a rough perimeter and demonstrate localization in angu lar momentum space. Because Schrodinger's wave mechanics and Maxwell's elec trodynamics are equivalent for a 2d cavity, we compare our experimental res ults directly with the quantum theory of rough 2d cavities [K.M. Frahm and D.L. Shepelyansky, Phys. Rev. Leu. 78 (1997) 1440]. Introducing the concept of effective roughness we find good qualitative agreement. (C) 2000 Publis hed by Elsevier Science B.V. All rights reserved.