Manipulations of Spin Waves by Photoelectrons in Ferromagnetic/Non-Ferromagnetic Alloyed Film

Spin waves are considered to be an alternative carrier with great promise for information sensing. The feasible excitation and low-power manipulation of spin waves still remain a challenge. In this regard, natural light enablings spin-wave tunability in Co60Al40-alloyed film is investigated. A reversible shift of the critical angle (from 81 degrees in the dark to 83 degrees under illumination) of the body spin-wave is achieved successfully Meanwhile, an eye-catching shift (817 Oe) of the ferromagnetic resonance (FMR) field is obtained optically, leading to changes in magnetic anisotropy. Based on the modified Puszkarski's surface inhomogeneity model, the control of spin-wave resonance (SWR) by sunlight can be understood by an effective photoelectron-doping-induced change of the surface magnetic anisotropy. Furthermore, the body spin wave is modulated stably with natural light illumination, confirming a non-volatile, reversible switching behavior. This work has both practical and theoretical importance for developing future sunlight-tunable magnonics/spintronics devices.