一维混合环中超导邻近效应中二聚化与准周期性的相互作用
Interplay of dimerization and quasiperiodicity in the superconducting proximity effect of a one-dimensional hybrid ring
- Indian Statistical Institute（印度统计研究所）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本研究通过自洽Bogoliubov-de Gennes形式，研究一维混合环中SSH二聚化与AAH准周期性对超导邻近效应的协同调控，发现二聚化决定配对振荡与穿透，准周期势增强空间不均匀性并抑制幅度。
AI中文摘要：
近期关于准晶和拓扑系统中超导邻近效应的研究，为探索准周期性和拓扑如何影响邻近诱导超导开辟了新的研究方向。在本工作中，我们利用自洽的Bogoliubov-de Gennes形式，研究了由自旋单态超导体和由三种不同晶格模型描述的正常区域组成的混合环中邻近诱导配对振幅的空间变化。我们首先考虑由对角Aubry-André-Harper (AAH)模型描述的正常区域。增加准周期势会增强诱导有序参数的空间涨落，同时逐渐抑制其在正常区域的幅度。在局域化转变之后，由于底层电子态的局域性质，邻近诱导配对被强烈削弱。随后，正常区域由Su-Schrieffer-Heeger (SSH)链建模，以研究跳跃二聚化的影响。弱的二聚化在诱导配对中引入振荡调制，这些振荡深入延伸到正常区域，而强的二聚化则限制这些振荡并显著减少超导关联的穿透。最后，我们研究了组合的SSH-AAH模型，以探索二聚化跳跃与准周期性之间的相互作用。结果表明，SSH二聚化决定了诱导配对的振荡行为和穿透，而AAH势增强了空间不均匀性并进一步减小其幅度。这两种效应共同为在准周期混合系统中控制邻近诱导超导提供了一种多功能的手段。
英文摘要：
Recent studies of the superconducting proximity effect in quasicrystalline and topological systems have opened up a new research direction for exploring how quasiperiodicity and topology influence proximity induced superconductivity. In this work, we investigate spatial variation of the proximity induced pairing amplitude in a hybrid ring composed of a spin singlet superconductor and a normal region described by three different lattice models using the self-consistent Bogoliubov-de Gennes formalism. We first consider the normal region described by the diagonal Aubry-André-Harper (AAH) model. Increasing the quasiperiodic potential enhances spatial fluctuations in the induced order parameter, while progressively suppressing its magnitude in the normal region. Beyond the localization transition, proximity-induced pairing is strongly diminished due to the localized nature of the underlying electronic states. The normal region is then modeled by the Su-Schrieffer-Heeger (SSH) chain to investigate the effect of hopping dimerization. Weak dimerization introduces oscillatory modulations in the induced pairing that extend deep into the normal region, whereas strong dimerization confines these oscillations and significantly reduces the penetration of superconducting correlations. Finally, we study the combined SSH-AAH model to explore the interplay between the dimerized hopping and quasiperiodicity. The results show that the SSH dimerization determines the oscillatory behavior and penetration of the induced pairing, while the AAH potential enhances spatial inhomogeneity and further reduces its magnitude. Together, these two effects provide a versatile means of controlling proximity-induced superconductivity in quasiperiodic hybrid systems.
