Superconducting phenomena in systems with unconventional magnets

In this work we review the recent advances on superconducting phenomena in junctions formed by superconductors and unconventional magnets (UM). Conventional magnets, such as ferromagnets and antiferromagnets, are characterized by broken time-reversal symmetry but only ferromagnets produce a finite net magnetization due to parallel spin alignment and spin-split bands in momentum. Very recently, a new type of magnets has been reported and here we refer to them asUMsbecause they exhibit special properties of both ferromagnets and antiferromagnets: they exhibit zero net magnetization (like antiferromagnets) and a nonrelativistic spin splitting of energy bands (like ferromagnets), both leading to anisotropic spin-polarized Fermi surfaces. An interesting property of UMs is that their magnetic order can be even or odd with respect to momentum, whered-wave altermagnetsandp-wave magnetsare the most representative examples. In this regard,d-wave altermagnets andp-wave magnets are seen as counterparts in magnetism of the unconventionald- andp-wave superconducting states, respectively. While the impact of conventional magnetism on superconductivity has been largely studied, the combination of UMs and superconductivity has only lately attracted considerably attention. This work provides a comprehensive review of the recent progress on the interplay between superconductivity and UMs. In particular, we focus on the fundamental emerging superconducting phenomena and also discuss the potential implications towards quantum applications.