Emergent scale and anomalous dynamics in certain quasi-periodic systems

We study localisation transition in a class of quasi-periodic systems that has two competing periodic scales. We show that such class of systems show a re-entrant localisation transition where the energy scale of transition is set by the periodicities of these two scales. Furthermore we show dynamical properties in these systems, exhibits various kinds critical dynamics including sub-diffusive, super-diffusive and diffusive spread of an initially localised wave-packet. Finally we show that these characteristics of quasi-periodic systems with two periodic scales can be realised within the regime of current experiments.