Abstract

The transport properties of the graphene-based antiferromagnet/insulator/ferromagnet/superconductor junction with noncollinear magnetic moments are theoretically investigated under the Bogoliubov-de Gennes equation. By introducing a mass term into the antiferromagnetic region, the spin-polarized equal-spin Andreev reflection (EAR) can be achieved for all voltages in the subgap region, free from any interference from the opposite-spin Andreev reflection (OAR). The transition from the retro EAR to the specular EAR can be realized by adjusting the Fermi level within the antiferromagnetic region. The perfect EAR can be obtained, suggesting an efficient equal-spin pairing correlation. Furthermore, we note that the EAR exhibits magnetoisotropy with an in-plane ferromagnetic exchange field, which is opposite to the results in a ferromagnet/ferromagnet/superconductor junction.

Graphical abstract

中文翻译：

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反铁磁石墨烯中的自旋极化等自旋安德烈夫反射

摘要

基于Bogoliubov-de Gennes方程，理论上研究了具有非共线磁矩的石墨烯基反铁磁体/绝缘体/铁磁体/超导体结的输运特性。通过在反铁磁区域引入质量项，可以对子带隙区域中的所有电压实现自旋极化等自旋安德烈夫反射（EAR），而不受反自旋安德烈夫反射（OAR）的任何干扰。从复古 EAR 到镜面 EAR 的转变可以通过调整反铁磁区域内的费米能级来实现。可以获得完美的 EAR，这表明存在有效的等自旋配对相关性。此外，我们注意到 EAR 表现出具有面内铁磁交换场的磁各向同性，这与铁磁体/铁磁体/超导体结中的结果相反。

图形概要