Anomalous diffusion in multichannel systems without a Lévy distribution of disorder

Abstract: We show that multichannel quantum systems with uncorrelated but asymmetric Anderson-type disorder can exhibit anomalous diffusion, even in the absence of heavy-tailed disorder. Using a minimal two-channel model with channel asymmetry, we demonstrate a crossover from normal to anomalous transport tuned by interchannel coupling. Applied to quasi-one-dimensional lattices with edge disorder, this leads to long-tailed transmission statistics characterized by ballistic segments interspersed with localized ones, reminiscent of L\'evy flights. This channel-asymmetric anomalous diffusion (CAAD) emerges from quantum interference between channels with differing disorder strengths. While CAAD governs transport at intermediate lengths, conventional localization prevails asymptotically, violating the Thouless relation. These results highlight a distinct quantum mechanism for anomalous diffusion beyond classical paradigms.