Oscillatory superconducting transition temperature in superconductor/antiferromagnet heterostructures

Abstract

One of the most famous proximity effects at ferromagnet/superconductor (F/S) interfaces is partial conversion of singlet superconductivity to triplet pairing correlations. Due to the presence of macroscopic exchange field in the ferromagnet the Cooper pairs penetrating into the ferromagnet from the superconductor acquire a finite momentum there. The finite-momentum pairing manifests itself, in particular, as a nonmonotonic dependence of the critical temperature of the bilayer on the thickness of the F layer. Here we predict that despite the absence of the macroscopic exchange field the critical temperature of the antiferromagnet/superconductor (AF/S) bilayers also exhibit nonmonotonic (oscillating) dependence on the AF layer thickness. It is a manifestation of the proximity-induced Neel-type triplet correlations, which acquire finite total pair momentum and oscillate in the AF layer due to the Umklapp electron scattering processes at the AF/S interface. Our prediction can provide a possible explanation for a number of recently published experimental observations of the critical temperature of AF/S bilayers.

References in corpus (6)

• Critical Current Oscillations in Strong Ferromagnetic Pi-Junctions
• Spin Insulatronics
• Josephson tunnel junctions with strong ferromagnetic interlayer
• Fabrication and measurements of hybrid Nb/Al Josephson junctions and flux qubits with pi-shifters
• Complete $T_c$ suppression and Néel triplets-mediated exchange in antiferromagnet-superconductor-antiferromagnet trilayers
• Magnetic anisotropy of superconducting transition in S/AF heterostructures with spin-orbit coupling

Cited by in corpus (7)

• Gate-tunable nonlocal Josephson effect through magnetic van der Waals bilayers
• Superconducting spin valves based on antiferromagnet/superconductor/antiferromagnet heterostructures
• Neel proximity effect in superconductor/antiferromagnet heterostructures
• Finite-momentum mixed singlet-triplet pairing in chiral antiferromagnets induced by even-parity spin texture
• Andreev bound states at nonmagnetic impurities in superconductor/antiferromagnet heterostructures
• Triplet correlations in superconductor/antiferromagnet heterostructures: dependence on type of antiferromagnetic ordering
• Influence of Magnetic Order on Proximity-Induced Superconductivity in Mn Layers on Nb(110) from First Principles