Reentrant Localization Transition in a Quasiperiodic Chain

Systems with quasiperiodic disorder are known to exhibit localization transition in low dimension. After a critical strength of disorder all the states of the system become localized, thereby ceasing the particle motion in the system. However, in our analysis we show that in a one dimensional dimerized lattice with staggered quasiperiodic disorder, after the localization transition some of the localized eigenstates become extended for a range of intermediate disorder strengths. Eventually, the system undergoes a second localization transition at a higher disorder strength leading to all states localized. We also show that the two localization transitions are associated with the mobility regions hosting the single particle mobility edges. We establish this re-entrant localization transition by analyzing the eigenspectra, participation ratios and the density of states of the system.