Efficient all-optical helicity-dependent switching in Pt/Co/Pt with dual laser pulses.

All-optical helicity-dependent switching (AO-HDS), deterministic control of magnetization by circularly polarized light pulses, allows to efficiently manipulate magnetization without the need of a magnetic field. While ferrimagnetic metals show single-shot magnetization switching, ferromagnetic metals require a large number of pulses to fully reverse the magnetic state from up to down or vice versa. Here, we demonstrate a drastic reduction in the number of pulses for full switching in a single stack of Pt/Co/Pt. To achieve this, we used pairs of optical pulses, a femtosecond linearly polarized pulse followed by a picosecond circularly polarized pulse. The obtained results suggest that the dual-pulse method is a potential route towards realizing efficient AO-HDS in ferromagnetic metals.