Spin Pinning and Spin-Wave Dispersion in Nanoscopic Ferromagnetic Waveguides.

Abstract in brief

• The study investigates spin waves in very thin yttrium iron garnet (YIG) waveguides with widths as small as 50nm, using Brillouin light scattering spectroscopy, and confirms the findings with theoretical models and computer simulations.
• A key discovery is that when the waveguide width falls below a certain critical size, the exchange interaction suppresses dipolar pinning, which alters how spinwave modes are quantized and changes their behavior.
• The developed semianalytical theory helps predict the patterns and dispersion (energy/momentum relationship) of spinwaves in these tiny magnetic structures.