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arXiv · 2308.15516

Coexistence of ergodic and weakly ergodic states in finite-height Wannier-Stark ladders

Xingbo Wei·Liangqing Wu·Kewei Feng·Tong Liu·Yunbo Zhang
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Abstract

We investigate a single-particle in one-dimensional Wannier-Stark ladders with either a linear potential or a mosaic potential with spacing $\kappa=2$. In both cases, we exactly determine the critical energies separating the weakly ergodic states from ergodic states for a finite potential height. Especially in the latter case, we demonstrate a rich phase diagram with ergodic states, weakly ergodic states, and strongly Wannier-Stark localized states. Our results also exhibit that critical energies are highly dependent on the height of the ladder and ergodic states only survive at $E\approx0$ for the high ladder. Importantly, we find that the number of ergodic states can be adjusted by changing the interval of the non-zero potential. These interesting features will shed light on the study of disorder-free systems.

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Xingbo Wei, Liangqing Wu, Kewei Feng, Tong Liu, Yunbo Zhang. 2023-08-29. Coexistence of ergodic and weakly ergodic states in finite-height Wannier-Stark ladders. https://doi.org/10.1103/physreva.109.023314

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