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arXiv 2102.04679cond-mat.supr-concond-mat.mes-hall
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通过自旋极化量子反常霍尔绝缘体的约瑟夫森结中的边诱导配对态

Edge-induced pairing states in a Josephson junction through a spin-polarized quantum anomalous Hall insulator

Ryota Nakai, Kentaro Nomura, Yukio Tanaka

摘要:

尽管量子霍尔系统的手征边缘模对超导邻近效应具有鲁棒性,但在适当的设置下,库珀对可以穿透手征边缘沟道并携带约瑟夫森电流。我们从符合手征边缘模的对对称性角度研究了自旋极化的量子反常霍尔绝缘体(QAHI)的约瑟夫森结,其Chern数为$ν=1$,连接常规超导体.诱导配对态是等自旋三重态,是偶数和奇数频率分量的组合,非局部扩展,具有有限动量$2k_F$。等自旋三重态配对的签名通过对界面磁化方向的依赖来确认,并且通过异常格林函数的空间轮廓来确认有限动量配对状态的签名。在存在无序的情况下,手征边缘模的鲁棒性导致临界电流和平衡相位差对无序组态的高灵敏度,这是由载流通道的干扰引起的。用简化的解析模型对格点模型的数值计算进行了检验。

英文摘要:

Despite the robustness of the chiral edge modes of quantum Hall systems against the superconducting proximity effect, Cooper pairs can penetrate into the chiral edge channels and carry the Josephson current in an appropriate setup. In our work, the Josephson junction of a spin-polarized quantum anomalous Hall insulator (QAHI) with a Chern number $ν=1$ connecting conventional superconductors is studied from the perspective of pairing symmetry consistent with the chiral edge mode. Induced pairing states are equal-spin triplet, a combination of the even- and odd-frequency components, nonlocally extended, and have a finite momentum $2k_F$. The signature of the equal-spin triplet pairings is confirmed via the dependence on the interface-magnetization direction, and that of the finite-momentum pairing states via the spatial profile of the anomalous Green's function. In the presence of disorder, the robustness of the chiral edge mode leads to high sensitivity of the critical current and the equilibrium phase difference to disorder configurations, which is resulting from the interference of current-carrying channels. The numerical calculations on a lattice model are also examined by a simplified analytical model.

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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