Enhanced controllable triplet proximity effect in superconducting spin–orbit coupled spin valves with modified superconductor/ferromagnet interfaces
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
In a superconductor/ferromagnet hybrid, a magnetically controlled singlet-to-triplet Cooper pair conversion can modulate the superconducting critical temperature. In these triplet superconducting spin valves, such control usually requires inhomogeneous magnetism. However, in the presence of spin–orbit coupling from an interfacial heavy metal layer, the singlet/triplet conversion rate and, thus, critical temperature can be controlled via the magnetization direction of a single homogeneous ferromagnet. Here, we report significantly enhanced controllable pair conversion to a triplet state in a Nb/Pt/Co/Pt superconducting spin valve in which Pt/Co/Pt is homogenously magnetized and proximity-coupled to a superconducting layer of Nb. The Co/Pt interface furthest away from Nb is modified by a sub-nanometer-thick layer of Cu or Au. We argue that the enhancement is most likely associated from an improvement of the Co/Pt interface due to the insertion of Cu and Au layers. Additionally, the higher normalized orbital moments in Au measured using x-ray magnetic circular dichroism shows that increasing spin–orbit coupling enhances the triplet proximity effect—an observation supported by our theoretical calculations. Our results provide a pathway to enhancing triplet pair creation by interface engineering for device development in superspintronics.
Date Issued
2024-04-15
Date Acceptance
2024-03-23
Citation
Applied Physics Letters, 2024, 124 (16)
ISSN
0003-6951
Publisher
AIP Publishing
Journal / Book Title
Applied Physics Letters
Volume
124
Issue
16
Copyright Statement
© 2024 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (https://
creativecommons.org/licenses/by/4.0/).
creativecommons.org/licenses/by/4.0/).
License URL
Identifier
https://doi.org/10.1063/5.0209305
Publication Status
Published
Article Number
162602
Date Publish Online
2024-04-16