A micro-sized parametric spin-wave amplifier

TL;DR

This paper experimentally demonstrates localized spin-wave amplification in a micro-sized NiFe magnonic waveguide using parallel pumping, revealing two distinct operational regimes depending on pumping power and timing.

Contribution

It introduces a micro-sized parametric spin-wave amplifier and analyzes its behavior under different pumping conditions using Brillouin light scattering spectroscopy.

Findings

Amplification depends on pumping power and timing.

Two operation regimes identified: large and low pumping powers.

Timing of spin-wave entry affects amplification success.

Abstract

We present the experimental observation of the localized amplification of externally excited spin waves in a transversely in-plane magnetized Ni$_{81}$Fe$_{19}$ magnonic waveguide by means of parallel pumping. By employing microfocussed Brillouin light scattering spectroscopy, we analyze the dependency of the amplification on the applied pumping power and on the delay between the input spin-wave packet and the pumping pulse. We show that there are two different operation regimes: At large pumping powers, the spin-wave packet needs to enter the amplifier before the pumping is switched on in order to be amplified while at low powers the spin-wave packet can arrive at any time during the pumping pulse.