Electrically Gated Laser-Induced Spin Dynamics in Magnetoelectric Iron Garnet at Room Temperature

Ultrafast pump-probe imaging reveals that the efficiency of optical excitation of coherent spin waves in epitaxial iron garnet films can be effectively controlled by an external electric field at room temperature. Although a femtosecond laser pulse alone does not excite any pronounced coherent spin oscillations, an electrical gating with the field of 0.5  MV/m dramatically changes the outcome in a laser-induced launching of spin waves. The effect, demonstrated under room-temperature conditions, is estimated to be orders of magnitude larger than in magnetic van der Waals semiconductors observed at 10 K. This electrical gating of laser-induced spin dynamics enriches optomagnonics with a new tool and thus opens up a new avenue in fundamental and applied magnonics research.