Speaker
Description
Mobility edges (MEs) that separate localized, multifractal, and ergodic states in energy are a central concept in understanding Anderson localization. In this work, we study the effect of an additional constant offset on the mobility-edge formation in the one-dimensional all-bands-flat (ABF) diamond chain with a quasiperiodic potential. We show that this offset can transform anomalous mobility edges (AMEs), i.e., boundaries separating localized and multifractal states, into conventional mobility edges separating localized and ergodic states. We further compare the numerically obtained ME structure with an analytical estimate motivated by Avila’s global theory. While the estimate provides useful insight into the mobility-edge formation, discrepancies with the numerical results appear both at a quantitative level, through shifts in the mobilityedge locations, and at a qualitative level, through the emergence of multiple mobility edges not captured by the analytical estimate.