Finite-momentum Cooper pairing in altermagnet/superconductor heterostructure

I will discuss two types of non-relativistic spin-splitting effects in metallic altermagnets, a class of unconventional antiferromagnets, and their role in generating finite-momentum Cooper pairings in an altermagnet/superconductor junction. The first type features anisotropic spin-splitting Fermi surfaces, while the second type exhibits isotropic splitting. For both cases, I will demonstrate how finite-momentum Cooper pairs can be induced in altermagnets despite the system having zero net magnetization, and show the differences in their proximity-induced order parameters. Thus, both can lead to controllable 0-pi transitions in the Josephson supercurrent. For the isotropic case, I will also discuss the possibility of proximity-induced equal-spin triplet pairing with odd frequency coexisting with spin-singlet pairing. If time permits, I will briefly discuss the impact of light irradiation on altermagnetic materials.

If you would like to meet with Lun-Hui during his visit, please contact Susan LaMoreaux.