Triplet proximity effect in superconducting heterostructures with a half-metallic layer

TL;DR

This paper uses the Usadel theory to analyze the superconducting proximity effect in heterostructures with a half-metallic layer, revealing a giant triplet spin-valve effect and $\

Contribution

It introduces a theoretical framework for understanding the triplet proximity effect in superconductor-half-metal systems, aligning with recent experimental observations.

Findings

Giant triplet spin-valve effect in S-F-HM trilayers

Formation of $\

results in qualitative agreement with recent experimental data on hybrid structures.

Abstract

We present the Usadel theory describing the superconducting proximity effect in heterostructures with a half-metallic layer. It is shown that the full spin polarization inside the half-metals gives rise to the giant triplet spin-valve effect in superconductor (S) - ferromagnet (F) - half-metal (HM) trilayers as well as to the $\varphi_0$-junction formation in the S/F/HM/F/S systems. In addition, we consider the exactly solvable model of the S/F/HM trilayers of atomic thickness and demonstrate that it reproduces the main features of the spin-valve effect found within the Usadel approach. Our results are shown to be in a qualitative agreement with the recent experimental data on the spin-valve effect in ${\rm MoGe/Cu/Ni/CrO_2}$ hybrids [A. Singh et al., Phys. Rev. X 5, 021019 (2015)].