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arXiv 2109.10201cond-mat.supr-con
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自旋分裂超导体结中的电流整流

Current rectification in junctions with spin-split superconductors

Stefan Ilić, P. Virtanen, T. T. Heikkilä, F. Sebastián Bergeret

摘要:

自旋分裂超导体表现出电子-空穴不对称的自旋分辨态密度,但在对自旋进行平均后,对称性会恢复。另一方面,非对称性再次出现在自旋分裂超导体与自旋极化势垒的隧道结。正如最近在理论和实验中所证明的那样,这一事实导致了超导铁磁结构中特别强的热电效应。在这项工作中,我们显示了另一个重要的影响,源于电子空穴的不对称性-电流整流。本文计算了正常金属和自旋分裂超导体的自旋极化隧道结在交流和直流偏压下的电荷电流。在DC情况下,I-V曲线不是完全反对称的,并且由于自旋极化而具有电压对称分量。这转化为在AC情况下整流电流的存在,其与结的自旋极化成比例,并且强烈地依赖于所施加的偏置的频率。我们讨论了整流效应的可能应用,包括用于超导电子学和辐射探测器的二极管。整流充电电流的分析是由热电流和相关的噪声消除器,其中电子空穴不对称性也起着重要的作用,并在检测器中的应用程序是有用的讨论补充。

英文摘要:

Spin-split superconductors exhibit an electron-hole asymmetric spin-resolved density of states, but the symmetry is restored upon averaging over spin. On the other hand, asymmetry appears again in tunneling junctions of spin-split superconductors with a spin-polarized barrier. As demonstrated recently in both theory and experiment, this fact leads to a particularly strong thermoelectric effect in superconductor-ferromagnet structures. In this work we show another important effect stemming from the electron-hole asymmetry - current rectification. We calculate the charge current in spin-polarized tunnel junctions of normal metal and a spin-split superconductor with AC and DC voltage bias. In the DC case, the I-V curve is not fully antisymmetric and has a voltage-symmetric component due to spin polarization. This translates to the existence of a rectified current in the AC case, which is proportional to the spin polarization of the junction and strongly depends on the frequency of the applied bias. We discuss possible applications of the rectification effect, including a diode for superconducting electronics and radiation detectors. The analysis of the rectified charge current is supplemented by the discussion of heat current and relevant noise correlators, where electron-hole asymmetry also plays an important role, and which are useful for applications in detectors.

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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