Model for multishot all-thermal all-optical switching in ferromagnets

J. Gorchon (1, 2) , Y. Yang (3) , J. Bokor (1, 2)

1 LBNL - Lawrence Berkeley National Laboratory [Berkeley]
2 Berkeley EECS - Department of Electrical Engineering and Computer Sciences
3 Department of Materials Science and Engineering [Berkeley]

All-optical magnetic switching (AOS) is a recently observed rich and puzzling phenomenon that offers promising technological applications. However, a fundamental understanding of the underlying mechanisms remains elusive. Here we present a model for multishot helicity-dependent AOS in ferromagnetic materials based on a purely heat-driven mechanism in the presence of magnetic circular dichroism (MCD). We predict that AOS should be possible with as little as 0.5% of MCD, after a minimum number of laser shots heat the sample close to the Curie temperature. Finally, we qualitatively reproduce the all-optically switched domain patterns observed experimentally by numerically simulating the result of multiple laser shots on an FePtC granular ferromagnetic film.

Domaines: Matière Condensée [cond-mat]

J. Gorchon, Y. Yang, J. Bokor. Model for multishot all-thermal all-optical switching in ferromagnets. Physical Review B: Condensed Matter and Materials Physics (1998-2015), 2016, 94 (2), ⟨10.1103/PhysRevB.94.020409⟩. ⟨hal-02105805⟩