Suppression of Spin Pumping at Metal Interfaces
Abstract
An electrically conductive metal typically transmits or absorbs a spin current. Here, we report on evidence that interfacing two metal thin films can suppress spin transmission and absorption. We examine spin pumping in ferromagnet/spacer/ferromagnet heterostructures, in which the spacer -- consisting of metallic Cu and Cr thin films -- separates the ferromagnetic spin-source and spin-sink layers. The Cu/Cr spacer largely suppresses spin pumping -- i.e., neither transmitting nor absorbing a significant amount of spin current -- even though Cu or Cr alone transmits a sizable spin current. The antiferromagnetism of Cr is not essential for the suppression of spin pumping, as we observe similar suppression with Cu/V spacers where V is a nonmagnetic analogue of Cr. We speculate that diverse combinations of spin-transparent metals may form interfaces that suppress spin pumping, although the underlying mechanism remains unclear. Our work may stimulate a new perspective on understanding and engineering spin transport in metallic multilayers.
Keywords
Cite
@article{arxiv.2305.01853,
title = {Suppression of Spin Pumping at Metal Interfaces},
author = {Youngmin Lim and Bhuwan Nepal and David A. Smith and Shuang Wu and Abhishek Srivastava and Prabandha Nakarmi and Claudia Mewes and Zijian Jiang and Adbhut Gupta and Dwight D. Viehland and Christoph Klewe and Padraic Shafer and In Jun Park and Timothy Mabe and Vivek P. Amin and Jean J. Heremans and Tim Mewes and Satoru Emori},
journal= {arXiv preprint arXiv:2305.01853},
year = {2023}
}