We study the spatio-temporal evolution of wave packets in one-dimensional quasiperiodic lattices which localize linear waves. Nonlinearity (related to two-body interactions) has destructive effect on localization, as recently observed for interacting atomic condensates [Phys. Rev. Lett. 106, 230403 (2011)]. We extend the analysis of the characteristics of the subdiffusive dynamics to large temporal and spatial scales. Our results for the second moment $m_2$ consistently reveal an asymptotic $m_2 \sim t^{1/3}$ and intermediate $m_2 \sim t^{1/2}$ laws. At variance to purely random systems [Europhys. Lett. 91, 30001 (2010)] the fractal gap structure of the linear wave spectrum strongly favors intermediate self-trapping events. Our findings give a new dimension to the theory of wave packet spreading in localizing environments.
Lyapunov spectrum scaling transition for quasiperiodic nonlinear unitaries
Institute for Basic Science（基础科学研究院）；Lanzhou University（兰州大学）；Qilu Normal University（齐鲁师范学院）；Korea University of Science and Technology (UST)（韩国科学技术院）；Max Planck Institute for the Physics of Complex Systems（马克斯·普朗克复杂系统物理研究所）；TU Dresden（德累斯顿工业大学）；Massey University（梅西大学）
Enhancement of chaotic subdiffusion in disordered ladders with synthetic gauge fields
本文研究了由人工规范场诱导的时间反演对称性破缺的无序非线性阶梯中的扩展波包。该模型在平均场近似下描述了无序驱动光梯中相互作用玻色子的动力学。波包的二阶矩$m_{2} = g t^α$以类似于时间反演情况的普适指数$α\simeq 1/3$亚扩散地增长。然而，前因子$g$强烈修改的电场强度，并显示出非单调依赖。对于弱场，前因子增加，因为时间反演增强后向散射被抑制。对于强场，线性波动方程的谱通过形成带隙和窄带来减小局域化长度。因此，抑制了次扩散律的前因子。
No measurement induced phase transition in the entanglement dynamics of monitored non-interacting one-dimensional fermions in a disordered or quasiperiodic potential
Shanghai Center for Complex Physics, School of Physics and Astronomy, Shanghai Jiao Tong University（上海交通大学物理与天文学院复杂物理中心）；Tsung-Dao Lee Institute, Shanghai Jiao Tong University（上海交通大学李政道研究所）；Institute for Quantum Materials and Technologies, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院量子材料与技术研究所）；Institut für Theorie der Kondensierten Materie, Karlsruhe Institute of Technology（卡尔斯鲁厄理工学院凝聚态理论研究所）
