In this paper, we propose a new algorithm, the irrational-window-filter projection method (IWFPM), for solving arbitrary dimensional global quasiperiodic systems. Based on the projection method (PM), IWFPM further utilizes the concentrated distribution of Fourier coefficients to filter out relevant spectral points using an irrational window. Moreover, a corresponding index-shift transform is designed to make the Fast Fourier Transform available. The corresponding error analysis on the function approximation level is also given. We apply IWFPM to 1D, 2D, and 3D quasiperiodic Schr\"odinger eigenproblems to demonstrate its accuracy and efficiency. IWFPM exhibits a significant computational advantage over PM for both extended and localized quantum states. Furthermore, the widespread existence of such spectral point distribution feature can endow IWFPM with significant potential for broader applications in quasiperiodic systems.
翻译:本文提出了一种新算法——无理窗滤波投影法(IWFPM),用于求解任意维度的全局准周期系统。该方法基于投影法(PM),进一步利用傅里叶系数的集中分布特性,通过无理窗滤除相关谱点。此外,设计了一种相应的指标平移变换,使得快速傅里叶变换得以应用。同时给出了函数逼近层面的相应误差分析。我们将IWFPM应用于一维、二维和三维准周期薛定谔本征问题,验证了其精度与效率。对于扩展态与局域化量子态,IWFPM均展现出相较于PM的显著计算优势。此外,此类谱点分布特征的广泛存在性,使得IWFPM在准周期系统中具备更广泛应用的巨大潜力。