Interface modes in planar one-dimensional magnonic crystals

TL;DR

This paper introduces the Zak phase for spin waves in planar magnonic crystals, analyzing interface modes and demonstrating bulk-edge correspondence through symmetry criteria and numerical verification.

Contribution

It develops a theoretical framework for interface modes in magnonic crystals using Zak phase and symmetry analysis, validated by numerical simulations.

Findings

Interface modes exist at boundaries between magnonic crystals with centrosymmetric unit cells.

Shifting the unit cell causes interface modes to traverse bandgap edges.

Theoretical results are verified numerically in exchange and exchange-dipolar regimes.

Abstract

We present the concept of Zak phase for spin waves in planar magnonic crystals and discuss the conditions for the existence of interface modes localized on the boundary between two magnonic crystals with centrosymmetric unit cells. Using the symmetry criterion and the calculated logarithmic derivative of the Bloch function we study the interface modes to demonstrate the bulk-edge correspondence. Our theoretical results are verified numerically for structures in the exchange and exchange-dipolar regimes and extended to the case in which one of the magnonic crystals has an arbitrary unit cell. Moreover, we show that by shifting the unit cell the interface modes can be caused to traverse the bandgap edges.