关联准周期性实现高效热电能量转换
Correlated quasiperiodicity enables efficient thermoelectric energy conversion
- Indian Statistical Institute（印度统计研究所）
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AI总结：
本研究利用关联准周期能量景观在纳米尺度一维链中实现高效热电转换，通过调节非公度参数使热电优值超过2，并系统分析了耦合与声子热导的影响，证明关联准周期纳米结构是高效热电材料的优选方案。
AI中文摘要：
我们研究了一种在纳米尺度系统中增强热电能量转换的途径，其核心是利用一维链中与源极和漏极储库耦合的关联准周期能量景观。所考虑的调制产生高度非均匀的电子透射谱，为实现高热电优值提供了有利条件。通过系统地调节非公度参数，我们探索了多种准周期构型，其中若干构型产生的优值超过2。电子输运性质在紧束缚框架内使用非平衡格林函数形式进行评估，而热电系数（包括电导、塞贝克系数和电子热导）则通过朗道方法确定。潜在的准周期势属于Aubry-André-Harper (AAH)族，并表现出弱变化的空间轮廓，从而产生有利于热电优化的透射特性。我们还详细分析了声子热导对整体能量转换效率的影响。为了完整性，我们还批判性地检查了导体与电极耦合以及耦合不对称性对ZT的影响。我们还检验了传统AAH系统的热电响应，并与我们所选的量子系统进行了详尽比较。我们的发现凸显了关联准周期纳米结构作为高效热电应用有前景候选者的潜力。
英文摘要：
We investigate a route to enhanced thermoelectric energy conversion in nanoscale systems by exploiting a correlated quasiperiodic energy landscape in a one-dimensional chain coupled to source and drain reservoirs. The considered modulation generates a highly non-uniform electronic transmission spectrum, providing favorable conditions for achieving a large thermoelectric figure of merit. By systematically tuning the incommensurability parameter, a variety of quasiperiodic configurations are explored, several of which yield high values of the figure of merit exceeding $2$. Electronic transport properties are evaluated within a tight-binding framework using the non-equilibrium Green's function formalism, while the thermoelectric coefficients, including electrical conductance, Seebeck coefficient, and electronic thermal conductance, are determined through the Landauer approach. The underlying quasiperiodic potential belongs to the Aubry-André-Harper (AAH) family and exhibits a weakly varying spatial profile, leading to transmission characteristics that are favorable for thermoelectric optimization. The influence of phonon thermal conductance on the overall energy-conversion efficiency is also analyzed in detail. For the sake of completeness, we also critically inspect the effect of conductor to electrode coupling and the coupling asymmetry on $ZT$. We also check the thermoelectric response of conventional AAH system and an elaborate comparison is made with our chosen quantum system. Our findings highlight the potential of correlated quasiperiodic nanostructures as promising candidates for efficient thermoelectric applications.
