Roles of heating and helicity in ultrafast all-optical magnetization switching in TbFeCo

Abstract

Using time-resolved magneto-optical Kerr effect (TR-MOKE) method, helicity-dependent all-optical magnetization switching (HD-AOS) is observed in ferrimagnetic TbFeCo films. The thermal effect and opto-magneto effects are separately justified after single circularly polarized laser pulse. The integral evolution of this ultrafast switching is characterized on different time scales and the defined magnetization reversal time of 460 fs is the fastest ever observed. Combining the heat effect and inverse Faraday effect (IFE), micromagnetic simulations based on a single macro-spin model are performed that reproduce HD-AOS following a linear reversal mechanism.