Non-symmetric spin-pumping in a multiferroic heterostructure

TL;DR

This study demonstrates that in a multiferroic heterostructure, spin pumping efficiency can be controlled by electric polarization, showing asymmetric behavior depending on magnetization and acoustic wave directions, unlike in non-ferroelectric substrates.

Contribution

It reveals electric polarization as a key factor influencing spin pumping in multiferroic heterostructures, introducing a new method for electric field control of spintronic phenomena.

Findings

Spin pumping efficiency varies with magnetization and wave vector reversal in LiNbO3-based heterostructures.

The effect is absent in non-ferroelectric Al2O3 substrates.

Electric polarization of LiNbO3 influences spin pumping, enabling electric field control.

Abstract

We present spin pumping experiments in Co/Pt bilayers grown on Al2O3(0001) and on ferroelectric Y-cut LiNbO3 substrates. Spin pumping is triggered by resonant ferromagnetic resonance induced by surface acoustic waves. We observe that spin pumping efficiency varies when both the magnetization vector and the acoustic wave vector are reversed in Pt/Co/LiNbO3. This phenomenon is not observed in Pt/Co/Al2O3. We propose that the in-plane electric polarization of LiNbO3 is at the origin of the observed phenomenon. These observations open up the perspective of an electric field control of spin pumping efficiency.