Generation of magnonic spin wave traps

Spatially resolved measurements of the magnetization dynamics induced by an intense laser pump-pulse reveal that the frequencies of resulting spin wave modes depend strongly on the distance to the pump center. This can be attributed to a laser generated temperature profile. On a CoFeB thin film magnonic crystal, Damon-Eshbach modes are expected to propagate away from the point of excitation. The experiments show that this propagation is frustrated by the strong temperature gradient