University of Barcelona
Strain Spin Waves
Spin waves in ferromagnets are coherent dispersive waves, typically in the low GHz frequency regime and with wavelengths of hundreds of nanometers. Recent interest for spin waves is motivated by the possibility of its integration into nano-scale devices for high-speed and low-power signal processing. However, generation of spin waves with high amplitudes—and their detection—is challenging due to the mismatch of wavelengths with electromagnetic waves in free space, which is of the order of several centimeters. Using hybrid systems composed of piezoelectric plus magnetic materials it is possible to create large amplitude spin waves with up to 25 degrees variation in the magnetization orientation. I will show direct images that quantify the "strain spin waves"—both standing and propagating—with different wavelengths, propagating over large distances up to several millimeters, orders of magnitude longer than previously achieved.
 Direct imaging of delayed magneto-dynamic modes induced by surface acoustic waves. Nature communications 8 (1), 407 (2017)