All-Optical Deterministic Switching of Synthetic CoCrPt Ferrimagnets*

Ultrafast magnetic switching via femtosecond laser pulses is vital for increasing the speed of spintronic devices and has been demonstrated in various ferrimagnetic materials. However, this switching has not yet been demonstrated in synthetic ferrimagnetic hcp CoPtCr alloys. The synthetic ferrimagnetic trilayers consist of two CoCrPt layers antiferromagnetically coupled via a thin Ru spacer. Synthetic ferrimagnetic thin film trilayers have the potential to be switched in the sub-picosecond time regime. CoCrPt is a highly anisotropic magnetic material with low saturation magnetization, making it optimal for magnetic recording. Here we demonstrate all-optical helicity-dependent switching of CoCrPt/Ru/CoCrPt thin film trilayers using circularly polarized, 65 femtosecond, 800 nm KrF laser pulses.