Timescales and contribution of heating and helicity effect in helicity-dependent all-optical switching

Abstract The heating and helicity effects induced by circularly polarized laser excitation are entangled in the helicity-dependent all-optical switching (HD-AOS), which hinders understanding magnetization dynamics involved. Here, applying a dual-pump excitation, first with linearly (LP) pulse followed (CP) pulse, timescales contribution from HD-AOS were identified Pt/Co/Pt triple-layer. When LP pulses preheat sample to nearly fully demagnetized state, CP power reduced 80% switch sample’s magnetization. By varying time delay between two pump pulses, results show that effect, gives rise deterministic helicity-induced switching, arises almost instantly within 200 fs close width upon excitation. reveal transient state impinge is key factor for achieving HD-AOS, importantly, tunability unique approach will enable wide range of magnetic material systems having wide-ranging implications potential ultrafast spintronics applications. Graphical abstract