Observation of spin-wave propagation in permalloy microstripes

TL;DR

This paper demonstrates the direct observation and measurement of spin-wave propagation, amplitude, phase velocity, and damping in permalloy microstripes using Kerr microscopy, revealing dominant interference modes.

Contribution

It provides the first direct measurement of spin-wave interference patterns and mode-specific velocities in permalloy microstripes, advancing understanding of spin-wave dynamics.

Findings

Dominant interference modes are m=0 and m=2.

Phase velocities are 71 km/s for m=0 and 47 km/s for m=2.

Spin-wave damping and amplitude are characterized for these modes.

Abstract

We report on the propagation of spin waves in permalloy microstripes. By means of scanning Kerr microscopy combined with continuous microwave excitation, we detect the time evolution of spin-wave interference patterns in an external magnetic field. Assuming transverse spin-wave quantization we can directly measure the amplitude, phase velocity and damping for the corresponding transversal wave mode numbers m. We find that the spin-wave interference pattern is dominated by m=0 and m=2 with phase velocities v_0=71 km/s and v_2=47 km/s, respectively.