发表机构
Department of Physics, National University of Singapore; Centre for Quantum Technologies, National University of Singapore（新加坡国立大学物理系; 新加坡国立大学量子技术中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究在实空间中探讨非线性如何与准周期势共同作用，诱导一维手性对称系统的拓扑相变，并指出边界局域化并非拓扑边缘态的可靠标志。
AI 中文摘要
非线性可以在周期系统中诱导拓扑相变。因此，检验这种相变在缺乏平移对称性的情况下是否仍然存在，具有相当大的研究意义。我们直接在实空间中处理这一问题，以周期性Su-Schrieffer-Heeger（SSH）链作为参考来理解准周期性的影响。研究发现，非线性如何驱动链向拓扑相变演化，强烈依赖于准周期势的强度。随着非线性强度的增加，我们发现弱准周期性支持从平庸相到拓扑相的转变，而中间区域则没有拓扑相变。在强准周期性下，明显的边界局域化可以在非线性诱导的拓扑转变之前就发展起来。我们的结果表明，非线性如何与准周期势相互作用以诱导拓扑相变，并且仅凭非线性本征态的边界局域化不能作为拓扑边缘态的明确标志。
英文摘要
Nonlinearity can induce topological phase transitions in periodic systems. It is hence of considerable interest to examine if such transitions persist in the absence of translational symmetry. We address this question directly in real space, using the periodic Su-Schrieffer-Heeger (SSH) chain as a reference for understanding the effect of quasiperiodicity. How nonlinearity drives a chain towards a topological phase transition is found to depend strongly on the strength of the quasiperiodic potential. As the nonlinearity strength increases, we find that weak quasiperiodicity supports a transition from a trivial to a topological phase, whereas the intermediate regime does not have a topological phase transition. Under strong quasiperiodicity, pronounced boundary localization can develop well before a nonlinearity-induced topological transition. Our results show how nonlinearity may interplay with a quasiperiodic potential in inducing topological phase transitions and that boundary localization of nonlinear eigenstates alone may not be taken as a clear signature of topological edge states.
Comments11+5 pages, 10+7 figures
