Avalanche stability transition in interacting quasiperiodic systems

Coupling a one-dimensional quasiperiodic interacting system to a Markovian bath, we study the avalanche instability of the many-body localized phase numerically, finding that many-body localization (MBL) is more stable in pseudorandom quasiperiodic systems than the corresponding randomly disordered systems for a disor-der strength W > 8, potentially up to arbitrarily large system sizes. We support our conclusion by additionally developing real-space RG arguments, and we provide a detailed comparison between quasiperiodic and random MBL from the avalanche instability perspective, concluding that the two belong to different universality classes.