Oscillatory Energy Exchange Between Waves Coupled by a Dynamic Artificial Crystal

TL;DR

This paper introduces a mechanism for controllable energy exchange between waves in a dynamic artificial crystal, demonstrated with spin waves in a magnonic crystal, where energy oscillates between coupled waves based on the imposed periodicity.

Contribution

It presents a novel method to control wave energy exchange via temporary periodicity in a medium, applicable to various wave systems.

Findings

Energy oscillates between coupled waves within the crystal.

Oscillation frequency depends on the spectral band gap width.

Demonstrated with spin waves in a magnonic crystal.

Abstract

We describe a general mechanism of controllable energy exchange between waves propagating in a dynamic artificial crystal. We show that if a spatial periodicity is temporarily imposed on the transmission properties of a wave-carrying medium whilst a wave is inside, this wave is coupled to a secondary counter-propagating wave and energy oscillates between the two. The oscillation frequency is determined by the width of the spectral band gap created by the periodicity and the frequency difference between the coupled waves. The effect is demonstrated with spin waves in a dynamic magnonic crystal.