THz emission from Fe/Pt spintronic emitters with L1$_{0}$-FePt alloyed interface

TL;DR

This study demonstrates that engineering the Fe/Pt interface with an L1$_{0}$-FePt alloy interlayer significantly enhances THz emission in spintronic emitters, offering new material design strategies.

Contribution

It introduces a novel trilayer structure with an alloyed interface that outperforms traditional bilayers in THz emission, advancing spintronic THz emitter technology.

Findings

Fe/L1$_{0}$-FePt (2 nm)/Pt structure shows higher THz emission amplitude.

THz emission depends on the extent of alloying at the interface.

Engineered interfaces can improve spintronic THz emitter performance.

Abstract

Recent developments in nanomagnetism and spintronics have enabled the use of ultrafast spin physics for terahertz (THz) emission. Spintronic THz emitters, consisting of ferromagnetic FM / non-magnetic (NM) thin film heterostructures, have demonstrated impressive properties for the use in THz spectroscopy and have great potential in scientific and industrial applications. In this work, we focus on the impact of the FM/NM interface on the THz emission by investigating Fe/Pt bilayers with engineered interfaces. In particular, we intentionally modify the Fe/Pt interface by inserting an ordered L1$_{0}$-FePt alloy interlayer. Subsequently, we establish that a Fe/L1$_{0}$-FePt (2\,nm)/Pt configuration is significantly superior to a Fe/Pt bilayer structure, regarding THz emission amplitude. The latter depends on the extent of alloying on either side of the interface. The unique trilayer structure opens new perspectives in terms of material choices for the next generation of spintronic THz emitters.