Selective Spin Wave Non-reciprocity in Engineered Chiral Magnonic Crystal without Dzyaloshinskii-Moriya Interaction

TL;DR

This paper demonstrates a new method to achieve spin wave non-reciprocity in engineered chiral magnonic crystals without relying on Dzyaloshinskii-Moriya interaction, enabling advanced magnonic device functionalities.

Contribution

The study introduces a novel approach to induce spin wave non-reciprocity through structural engineering of chiral magnonic crystals, bypassing the need for DMI.

Findings

Achieved tunable spin wave non-reciprocity via structural chirality.

Controlled spin wave directionality with external magnetic fields.

Potential for on-chip magnonic diodes with predefined pathways.

Abstract

Chirality is pivotal in magnonics, particularly for achieving spin wave non-reciprocity which is critical in advancing spin wave based communication and logic operations. In general, chirality in magnetic systems is realized through the interfacial antisymmetric exchange interaction, namely, the Dzyaloshinskii-Moriya Interaction (DMI), which is an intrinsic phenomenon occurring at the buried interface of ferromagnet and heavy metal. In this work, using micromagnetic simulations, we present a new route to achieve spin wave nonreciprocity using an engineered chiral magnonic crystal, where we artificially created in-plane twisted spin textures by imposing certain handedness in the structural geometry. The manipulation of the relative arrangement of these chiral enantiomers led to spin wave non-reciprocity, which could be tuned by selecting different channels within the crystal, with additional versatility in the resonant mode frequency. Further adjustment of the external magnetic field strength confirms that the spin wave directionality originates from the spin texture. This enables additional control over the band gap and mode propagation characteristics by external field tuning. Our work provides a novel and innovative route to simultaneously access opposite spin wave directions in consecutive channels, which makes this system competent for real on-chip magnonic diode, with predefined paths for counter-propagating information.