Magnonic band structure of a two-dimensional magnetic superlattice

TL;DR

This paper investigates the magnonic band structure in a 2D magnetic superlattice, deriving the exchange field boundary conditions and identifying material combinations that create complete band gaps.

Contribution

It introduces a theoretical framework for calculating spin wave spectra in 2D magnetic superlattices and identifies conditions for full magnonic band gaps.

Findings

Derived the exchange field boundary conditions for surface-torque-free interfaces.

Identified material combinations that produce complete magnonic band gaps.

Calculated the spin wave frequencies and linewidths in the superlattice.

Abstract

The frequencies and linewidths of spin waves in a two-dimensional periodic superlattice of magnetic materials are found, using the Landau-Lifshitz-Gilbert equations. The form of the exchange field from a surface-torque-free boundary between magnetic materials is derived, and magnetic-material combinations are identified which produce gaps in the magnonic spectrum across the entire superlattice Brillouin zone for hexagonal and square-symmetry superlattices.