Enhancement of Pure Spin Currents in Spin Pumping Y3Fe5O12/Cu/metal Trilayers through Spin Conductance Matching

TL;DR

This study demonstrates that inserting a copper layer in Y3Fe5O12/Cu/W heterostructures significantly enhances spin current injection by matching spin conductances, unlike in Y3Fe5O12/Cu/Pt where it degrades the spin current.

Contribution

It reveals the importance of spin conductance matching in heterostructures and shows how inserting a Cu layer can optimize spin transport efficiency.

Findings

Copper insertion improves spin current in Y3Fe5O12/Cu/W by over 4 times.

Inserting Cu in Y3Fe5O12/Cu/Pt degrades spin current.

Matching spin conductances enhances spin transport efficiency.

Abstract

Spin transport efficiency in heterostructures depends on the spin conductances of each constituent and their interfaces. We report a comparative study of spin pumping in Y3Fe5O12/Cu/Pt and Y3Fe5O12/Cu/W trilayers. Surprisingly, the insertion of a Cu interlayer between Y3Fe5O12 and W substantially improves (over a factor of 4) the spin current injection into W while similar insertion between Y3Fe5O12 and Pt degrades the spin current. This is a consequence of a much improved Y3Fe5O12/Cu spin mixing conductance relative to that for Y3Fe5O12/W. This result implies the possibility of engineered heterostructures with matching spin conductances to enable optimal spin transport efficiency.