Karmakar Sourav, Ganguly Sudin, Maiti Santanu K
Physics and Applied Mathematics Unit, Indian Statistical Institute, 203 Barrackpore Trunk Road, Kolkata 700 108, India.
Department of Physics, School of Applied Sciences, University of Science and Technology Meghalaya, Ri-Bhoi 793 101, India.
J Phys Condens Matter. 2025 Sep 11;37(37). doi: 10.1088/1361-648X/ae025a.
Quasiperiodic systems are known to exhibit localization transitions in low dimensions, wherein all electronic states become localized beyond a critical disorder strength. Interestingly, recent studies have uncovered a reentrant localization (RL) phenomenon: upon further increasing the quasiperiodic modulation strength beyond the localization threshold, a subset of previously localized states can become delocalized again within a specific parameter window. While RL transitions have been primarily explored in systems with simple periodic modulations, such as dimerized or long-range hopping integrals, the impact of more intricate or correlated hopping structures on RL behavior remains largely elusive. In this work, we investigate the localization behavior in a one-dimensional lattice featuring staggered, correlated on-site potentials following the Aubry-André-Harper model, along with off-diagonal hopping modulations structured according to quasiperiodic Fibonacci and Bronze mean sequences. By systematically analyzing the fractal dimension, inverse participation ratio, and normalized participation ratio, we demonstrate the occurrence of RL transitions induced purely by the interplay between quasiperiodic on-site disorder and correlated hopping. We further examine the parameter space to determine the specific regimes that give rise to RL. Our findings highlight the crucial role of underlying structural correlations in governing localization-delocalization transitions in low-dimensional quasiperiodic systems, where the correlated disorder manifests in both diagonal and off-diagonal terms.
已知准周期系统在低维情况下会表现出局域化转变，即在临界无序强度之上，所有电子态都会变为局域化。有趣的是，最近的研究发现了一种重入局域化（RL）现象：当准周期调制强度进一步增加到超过局域化阈值时，一部分先前局域化的态会在特定参数窗口内再次变为非局域化。虽然RL转变主要在具有简单周期调制的系统中进行了探索，例如二聚化或长程跳跃积分，但更复杂或相关的跳跃结构对RL行为的影响在很大程度上仍然不清楚。在这项工作中，我们研究了一个一维晶格中的局域化行为，该晶格遵循奥布里 - 安德烈 - 哈珀模型具有交错的、相关的在位势，以及根据准周期斐波那契和青铜平均序列构建的非对角跳跃调制。通过系统地分析分形维数、逆参与率和归一化参与率，我们证明了由准周期在位无序和相关跳跃之间的相互作用纯粹诱导的RL转变的发生。我们进一步研究参数空间以确定导致RL的特定区域。我们的发现突出了潜在结构相关性在低维准周期系统中控制局域化 - 非局域化转变的关键作用，其中相关无序在对角项和非对角项中都有体现。
