Coupled identical localized fermionic chains with quasirandom disorder

We analyze the ground-state localization properties of an array of identical interacting spinless fermionic chains with quasirandom disorder, using nonperturbative renormalization-group methods. In the single- or two-chain case localization persists, while for a larger number of chains a different qualitative behavior is generically expected, unless the many-body interaction is vanishing. This is due to number-theoretical properties of the frequency, similar to the ones assumed in Kolmogorov-Arnold-Moser theory, and cancellations due to the Pauli principle, which in the single- or two-chain case imply that all the effective interactions are irrelevant; in contrast, for a larger number of chains, relevant effective interactions are present.