# Controlled spin-to-charge conversion in noncollinear antiferromagnet-based Py/Mn$_{3}$Pt heterostructure

## TL;DR

This study demonstrates efficient spin-to-charge conversion in Py/Mn₃Pt heterostructures, highlighting noncollinear antiferromagnets as promising materials for ultrafast spintronic devices through broadband ferromagnetic resonance measurements.

## Contribution

It provides the first systematic investigation of magnetization dynamics and spin pumping in Py/Mn₃Pt bilayers, establishing their potential for high-performance spintronic applications.

## Key findings

- Enhanced damping indicates efficient spin pumping into Mn₃Pt
- Effective spin-mixing conductance comparable to other antiferromagnetic heterostructures
- Gilbert damping remains predominantly Gilbert type across frequencies

## Abstract

Noncollinear antiferromagnets (NCAFs) have recently emerged as promising candidates for future spintronic technologies, offering ultrafast switching, negligible stray fields allowing dense packing, and robustness against external magnetic perturbations. When interfaced with ferromagnets (FMs), they can strongly influence interfacial exchange and spin-torque mechanisms that enable manipulating magnetic order and realizing functionalities beyond conventional heavy metals (HMs) based FM/HM heterostructures. Here, we perform a broadband ferromagnetic resonance (FMR) study to systematically investigate the magnetization dynamics and spin-to-charge conversion in permalloy (Py) and Mn$_3$Pt bilayers. High-quality Py films provide a well-defined FMR spectra with a low Gilbert damping parameter ( $\alpha_{\mathrm{eff}} \approx 9.8 \times 10^{-3}$). We observe a pronounced enhancement of damping with intrinsic value $\alpha_{\mathrm{int}} \approx 3.1 \times 10^{-2}$ in the Py/Mn$_3$Pt bilayer, indicating efficient spin pumping into the NCAF layer. Frequency dependent linewidth analysis shows a predominantly Gilbert type damping in the bilayers and the corresponding effective spin-mixing conductance ( $g^{\uparrow\downarrow}_{\mathrm{eff}} \approx 4.8 \times 10^{18}$m$^{-2}$) is comparable to that of other high-performance antiferromagnetic heterostructures. These results are significant for establishing NCAFs as a candidate material for spin generation and highlights the potential of Py/Mn$_3$Pt bilayers for efficient and ultrafast spintronic applications.