Mobility edges and critical regions in periodically kicked incommensurate optical Raman lattice

TL;DR

This paper investigates the rich localization phenomena, including mobility edges and critical phases, in a periodically kicked incommensurate optical Raman lattice, revealing complex phase diagrams and experimental detection methods.

Contribution

It introduces a detailed phase diagram with multiple phases and mobility edges in a kicked quasiperiodic lattice, highlighting the fragility and reentrant localization transitions.

Findings

Identified critical, extended, and localized phases in the system.

Discovered mobility edges separating critical from other phases.

Proposed experimental detection via expansion dynamics.

Abstract

Conventionally the mobility edge (ME) separating extended states from localized ones is a central concept in understanding Anderson localization transition. The critical state, being delocalized and non-ergodic, is a third type of fundamental state that is different from both the extended and localized states. Here we study the localization phenomena in a one dimensional periodically kicked quasiperiodic optical Raman lattice by using fractal dimensions. We show a rich phase diagram including the pure extended, critical and localized phases in the high frequency regime, the MEs separating the critical regions from the extended (localized) regions, and the coexisting phase of extended, critical and localized regions with increasing the kicked period. We also find the fragility of phase boundaries, which are more susceptible to the dynamical kick, and the phenomenon of the reentrant localization transition. Finally, we demonstrate how the studied model can be realized based on current cold atom experiments and how to detect the rich physics by the expansion dynamics. Our results provide insight into studying and detecting the novel critical phases, MEs, coexisting quantum phases, and some other physics phenomena in the periodically kicked systems.