Controlling High-Frequency Spin-Wave Dynamics Using Double-Pulse Laser Excitation

Abstract

Manipulating spin waves is highly required for the development of innovative data transport and processing technologies. Recently, the possibility of triggering high-frequency standing spin waves in magnetic insulators using femtosecond laser pulses was discovered, raising the question about how one can manipulate their dynamics. Here we explore this question by investigating the ultrafast magnetization and spin wave dynamics induced by double-pulse laser excitation. We demonstrate a suppression or enhancement of the amplitudes of the standing spin waves by precisely tuning the time delay between the two pulses. The results can be understood as the constructive or destructive interference of the spin-waves induced by the first and second laser pulses. Our findings open exciting perspectives towards generating singlemode standing spin waves that combine high frequency with large amplitude and low magnetic damping.

Transient Non‐Collinear Magnetic State for All‐Optical Magnetization Switching

“…[ 1 ] Among the most prominent examples are the demonstration of ultrafast quenching of the magnetization, [ 2 , 3 ] single, [ 4 , 5 ] and multiple, [ 6 , 7 ] pulse AOS, optically induced magnetic phase transitions, [ 8 , 9 , 10 ] and optical excitation of spin‐waves. [ 11 , 12 , 13 ] In these cases, the investigations aimed to understand the ultrafast dynamics initiated by significant energy deposition to the system, also causing a reduction of the magnetization. On the other hand, ultrafast magnetization manipulation methods that do not cause magnetization suppression are much less explored.…”