标题： 约瑟夫森效应和非常规磁体超导结中的奇频配对 显示英文标题

标题： Josephson effect and odd-frequency pairing in superconducting junctions with unconventional magnets

摘要： 我们考虑通过非常规磁体耦合两个常规超导体形成的约瑟夫森结，并研究安德烈夫束缚态的形成、它们对约瑟夫森效应的影响以及出现的超导关联。我们关注已知的非常规磁体，即$d$波交替磁体和$p$波磁体。我们发现，在$d$波交替磁体和$p_y$波磁体约瑟夫森结中的安德烈夫束缚态强烈依赖于横向动量，其自旋分裂和低能极小值作为超导相位差$\varphi$的函数。相反，$p_{x}$波磁体的安德烈夫束缚态对横向动量不敏感。 我们证明Andreev束缚态可以通过结中间的局域态密度进行探测，这也表明$d_{x^{2}-y^{2}}$-和$p$-波磁结容易拥有零能峰。 虽然$d_{x^{2}-y^{2}}$-波反铁磁结中的零能峰会随着磁序而振荡，但在$p$-波磁结中则保持稳定。 我们还证明，在$d$-波反铁磁约瑟夫森结中的临界电流随着磁序的增加表现出振荡衰减，而在$p$-波磁结中振荡消失，尽管电流仍表现出缓慢衰减。 此外，我们还证明了约瑟夫森效应与$d$-wave altermagnets 和$p$-wave 磁体的非常规磁序之间的相互作用源于奇频自旋三重态$s$-wave 超导关联，这些关联在其他情况下是不存在的。 我们的结果可以作为探索基于非常规磁体的约瑟夫森结新功能的指导。 显示英文摘要

摘要： We consider Josephson junctions formed by coupling two conventional superconductors via an unconventional magnet and investigate the formation of Andreev bound states, their impact on the Josephson effect, and the emergent superconducting correlations. We focus on unconventional magnets known as $d$-wave altermagnets and $p$-wave magnets. We find that the Andreev bound states in $d$-wave altermagnet and $p_y$-wave magnet Josephson junctions strongly depend on the transverse momentum, with a spin splitting and low-energy minima as a function of the superconducting phase difference $\varphi$. In contrast, the Andreev bound states for $p_{x}$-wave magnets are insensitive to the transverse momentum. We show that the Andreev bound states can be probed by the local density of states in the middle of the junction, which also reveals that $d_{x^{2}-y^{2}}$- and $p$-wave magnet junctions are prone to host zero energy peaks. While the zero-energy peak in $d_{x^{2}-y^{2}}$-wave altermagnet junctions tends to oscillate with the magnetic order, it remains robust in $p$-wave magnet junctions. We also demonstrate that the critical currents in $d$-wave altermagnet Josephson junctions exhibit an oscillatory decay with the increase of the magnetic order, while the oscillations are absent in $p$-wave magnet junctions albeit the currents exhibit a slow decay. Furthermore, we also demonstrate that the interplay of the Josephson effect and unconventional magnetic order of $d$-wave altermagnets and $p$-wave magnets originates from odd-frequency spin-triplet $s$-wave superconducting correlations that are otherwise absent. Our results can serve as a guide to pursue the new functionality of Josephson junctions based on unconventional magnets.