Wide-range wavevector selectivity of magnon gases in Brillouin light scattering spectroscopy

TL;DR

This paper presents an improved Brillouin light scattering spectroscopy technique that achieves wide-range wavevector selectivity in two dimensions, enabling detailed analysis of spin waves with various orientations and wavevectors.

Contribution

The authors develop a novel setup that significantly enhances wavevector selectivity in BLS spectroscopy, allowing simultaneous measurement of dipole- and exchange-dominated spin waves in multiple orientations.

Findings

Wavevector selectivity up to 2.04×10^5 rad/cm achieved.

Simultaneous analysis of spin waves of any orientation.

Enhanced two-dimensional wavevector resolution in BLS spectroscopy.

Abstract

Brillouin light scattering spectroscopy is a powerful technique for the study of fast magnetization dynamics with both frequency- and wavevector resolution. Here, we report on a distinct improvement of this spectroscopic technique towards two-dimensional wide-range wavevector selectivity in a backward scattering geometry. Spin-wave wavevectors oriented perpendicular to the bias magnetic field are investigated by tilting the sample within the magnet gap. Wavevectors which are oriented parallel to the applied magnetic field are analyzed by turning the entire setup, including the magnet system. The setup features a wide selectivity of wavevectors up to 2.04\cdot 10E5 rad/cm for both orientations, and allows selecting and measuring wavevectors of dipole- and exchange-dominated spin waves of any orientation to the magnetization simultaneously.