时 间：2026年6月18日14:00-15：00
地 点：11号楼302会议室
报告题目：Generalized Aubry-Andre-Harper model with power-law quasiperiodic potentials
报告人：孙高永，副研究员（南京航空航天大学）
报告人简介：
孙高永，副研究员。2015年于德国汉诺威大学获得博士学位，2015-2017年在德国马克斯普朗克复杂系统物理研究所从事博士后研究，2017年在南京航空航天大学工作。迄今为止，在Phys. Rev. Lett., Phys. Rev. A/B/Research 等期刊上发表学术论文30余篇。
学术报告摘要：
We investigate a generalized Aubry-Andre-Harper (AAH) model with non-reciprocal hopping and power-law quasiperiodic potentialsV(i)=V[cos(2πβi)]p. Our study reveals that the interplay between nonreciprocity, quasiperiodicity, and the power-law exponent p gives rise to a variety of phase transitions and localization phenomena. In the Hermitian case, the system undergoes a direct transition from extended to localized phases for p=1, 2, while for p >= 3, an intermediate mixed phase emerges, characterized by the coexistence of extended and localized states and the presence of mobility edges. Importantly, we find that prominent high-IPR states associated with well-resolved spectral gaps appear at specific energy levels, whose positions are captured by the relation x_n=nβ-nβ」, for low-order n. In the non-Hermitian regime, the energy spectrum becomes complex and the PT transition coincides with the extended-to-localized phase boundary for p = 1, 2, whereas for p>=3, PT-symmetry breaking occurs at the mixed-to-localized phase transition. This work reveals how power-law quasiperiodic potentials and non-reciprocal hopping govern phase transitions, providing new insight into localization phenomena of quasiperiodic systems.
数理学院
2026年5月19日