# Dynamical amplification of magnetoresistances and Hall currents up to the THz regime

## TL;DR

This paper demonstrates that dynamical effects in Co/Pt and Fe/W bilayers can significantly amplify magnetoresistances and Hall currents at THz frequencies, with phase differences playing a crucial role in these phenomena.

## Contribution

It reveals how phase differences influence dynamical currents and shows giant enhancements of spin Hall angles near ferromagnetic resonance in bilayer systems.

## Key findings

- Dynamical spin Hall angles can change sign and increase over 500%.
- Charge and spin pumping can significantly modify magnetoresistive and Hall effects.
- Giant dynamical effects occur near ferromagnetic resonance in bilayers.

## Abstract

Spin-orbit-related effects offer a highly promising route for reading and writing information in magnetic units of future devices. These phenomena rely not only on the static magnetization orientation but also on its dynamics to achieve fast switchings that can reach the THz range. In this work, we consider Co/Pt and Fe/W bilayers to show that accounting for the phase difference between different processes is crucial to the correct description of the dynamical currents. By tuning each system towards its ferromagnetic resonance, we reveal that dynamical spin Hall angles can non-trivially change sign and be boosted by over 500%, reaching giant values. We demonstrate that charge and spin pumping mechanisms can greatly magnify or dwindle the currents flowing through the system, influencing all kinds of magnetoresistive and Hall effects, thus impacting also dc and second harmonic experimental measurements.