涡旋束缚态与杂质束缚态之间的量子干涉增强热电效应
Quantum interference between vortex- and impurity-bound states boosts thermoelectricity
- Norwegian University of Science and Technology（挪威科技大学）
机构由 AI 辅助整理，请以论文原文为准。
AI总结：
本文通过晶格Bogoliubov-de Gennes方法研究涡旋或杂质束缚态重叠时的量子干涉，发现该干涉可显著增强s波和d波超导体的局域热电响应，为低温热电传感与能量转换提供新途径。
AI中文摘要：
超导体中的热电效应通常因准粒子谱的近似粒子-空穴对称性而受到抑制，但在具有粒子-空穴不对称束缚态的缺陷附近，热电效应可以变得显著。本文研究了当多个涡旋或非磁性杂质彼此靠近时，局域热电响应如何被改变。我们采用晶格Bogoliubov-de Gennes方法结合线性响应隧穿理论，计算了s波和d波超导体中空间分辨的态密度和Seebeck系数。我们发现，当空间上扩展的缺陷诱导态发生重叠时，热电响应可以被强烈增强。对于涡旋，这种增强持续到核心区域之外，并源于涡旋束缚态之间的干涉。对于杂质，在s波和d波情形下，热电响应随杂质间距的变化表现出类似的依赖性，尽管在s波超导体中相关的谱重构明显更为局域化。我们的结果表明，缺陷诱导准粒子态的空间范围和干涉为控制非均匀超导体中的局域热电性提供了一种手段，并可能对低温热电传感和能量转换具有潜在意义。
英文摘要：
Thermoelectric effects in superconductors are generally suppressed by the approximate particle-hole symmetry of the quasiparticle spectrum, but can become pronounced near defects that host particle-hole asymmetric bound states. Here, we investigate how the local thermoelectric response is modified when multiple vortices or nonmagnetic impurities are brought into proximity. Using a lattice Bogolioubov-de Gennes approach combined with linear-response tunneling theory, we calculate the spatially resolved density of states and Seebeck coefficient in $s$- and $d$-wave superconductors. We find that the thermoelectric response can be strongly enhanced when spatially extended defect-induced states overlap. For vortices, this enhancement persists beyond the immediate core regions and originates from interference between vortex-bound states. For impurities, the thermoelectric response exhibits a comparable dependence on impurity separation in the $s$- and $d$-wave cases, although the associated spectral reconstruction is considerably more localized in the $s$-wave superconductor. Our results show that the spatial extent and interference of defect-induced quasiparticle states provide a means of controlling local thermoelectricity in inhomogeneous superconductors, with potential relevance for cryogenic thermoelectric sensing and energy conversion.
