Indirect excitation of ultrafast demagnetization

Indirect excitation of ultrafast demagnetization

Does the excitation of ultrafast magnetization require direct interaction between the photons of the optical pump pulse and the magnetic layer? Here, we demonstrate unambiguously that this is not the case. For this we have studied the magnetization dynamics of a ferromagnetic cobalt/palladium multilayer capped by an IR-opaque aluminum layer. Upon excitation with an intense femtosecond-short IR ...

Laser-induced ultrafast demagnetization in ferromagnetic metals.

The laser-induced femtosecond demagnetization in ferromagnetic metals is investigated theoretically. Different from the conventional nanosecond one, this ultrafast demagnetization is a cooperative effect of the external laser field and the internal spin-orbit coupling. The spin-orbit coupling smears out the original identities of triplets and singlets while the laser field uses it as an avenue ...

Nanorod Surface Plasmon Enhancement of Laser-Induced Ultrafast Demagnetization

Ultrafast laser-induced magnetization dynamics in ferromagnetic thin films were measured using a femtosecond Ti:sapphire laser in a pump-probe magneto-optic Kerr effect setup. The effect of plasmon resonance on the transient magnetization was investigated by drop-coating the ferromagnetic films with dimensionally-tuned gold nanorods supporting longitudinal surface plasmon resonance near the cen...

Feedback effect during ultrafast demagnetization dynamics in ferromagnets.

Motivated by the recent controversy about the importance of spin-flip scattering for ultrafast demagnetization in ferromagnets, we study the spin-dependent electron dynamics based on a dynamical Elliott-Yafet mechanism. The key improvement to earlier approaches is the use of a modified Stoner model with a dynamic exchange splitting between majority and minority bands. In the framework of our mi...

Bias-controlled ultrafast demagnetization in magnetic tunnel junctions