# Ultra-fast magnetization manipulation using single femtosecond light and hot-electrons pulse

## TL;DR

This study demonstrates that single femtosecond hot-electron pulses can deterministically reverse magnetization in GdFeCo alloys within 5 ps, offering a promising ultrafast, energy-efficient approach for spintronic applications.

## Contribution

It introduces the use of hot-electron pulses for ultrafast magnetization reversal, comparable to laser pulses, advancing spintronic manipulation techniques.

## Key findings

- Magnetization reversal occurs within 5 ps for both laser and hot-electron pulses.
- Hot-electron pulses enable deterministic switching in GdFeCo alloys.
- Energy efficiency is enhanced through ballistic hot-electron transport.

## Abstract

Current induced magnetization manipulation is a key issue for spintronic application. Therefore, deterministic switching of the magnetization at the picoseconds timescale with a single electronic pulse represents a major step towards the future developments of ultrafast spintronic. Here, we have studied the ultrafast magnetization dynamics in engineered Gdx[FeCo]1-x based structure to compare the effect of femtosecond laser and hot-electrons pulses. We demonstrate that a single femtosecond hot-electrons pulse allows a deterministic magnetization reversal in either Gd-rich and FeCo-rich alloys similarly to a femtosecond laser pulse. In addition, we show that the limiting factor of such manipulation for perpendicular magnetized films arises from the multi-domain formation due to dipolar interaction. By performing time resolved measurements under various field, we demonstrate that the same magnetization dynamics is observed for both light and hot-electrons excitation and that the full magnetization reversal take place within 5 ps. The energy efficiency of the ultra-fast current induced magnetization manipulation is optimized thanks to the ballistic transport of hot-electrons before reaching the GdFeCo magnetic layer.

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Source: https://tomesphere.com/paper/1704.03749