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arXiv 1803.03312cond-mat.mes-hall
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分子热机:量子相干性效应

Molecular Heat Engines: Quantum Coherence Effects

Feng Chen, Yi Gao, Michael Galperin

摘要:

纳米尺度实验技术的最新发展使得利用单分子结作为电子学和能量传递器件成为可能,其中量子相干性在其热电特性中起着重要作用。对纳米器件效率的理论研究通常采用速率(泡利)方程,该方程不考虑量子相干性。因此,量子相干性是否可以提高分子器件的效率的问题不能在这样的考虑中完全解决。在这里,我们采用非平衡格林函数方法来研究量子相干性和失相对分子热机热电性能的影响。在一个通用的双色施主-桥-受主结模型,我们表明,量子相干性可能会增加效率相比,准经典(速率方程)的预测和纯退相和耗散破坏这种效果。

英文摘要:

Recent developments in nanoscale experimental techniques made it possible to utilize single molecule junctions as devices for electronics and energy transfer with quantum coherence playing an important role in their thermoelectric characteristics. Theoretical studies on the efficiency of nanoscale devices usually employ rate (Pauli) equations, which do not account for quantum coherence. Therefore, the question whether quantum coherence could improve the efficiency of a molecular device cannot be fully addressed within such considerations. Here, we employ a nonequilibrium Green function approach to study the effects of quantum coherence and dephasing on the thermoelectric performance of molecular heat engines. Within a generic bichromophoric donor-bridge-acceptor junction model, we show that quantum coherence may increase efficiency compared to quasi-classical (rate equation) predictions and that pure dephasing and dissipation destroy this effect.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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