Terahertz pulse-induced Néel vector switching in α-Fe2O3/Pt heterostructures

Abstract

The increasing interest in antiferromagnetic electronics is driven by the vision of the operation in the terahertz regime and ultrahigh density memories. The use of a terahertz wave to scale up the writing speed to terahertz has been reported in the antiferromagnetic single layer CuMnAs with sublattice symmetry broken. Here, a reversible and reproducible switching in antiferromagnetic insulators α-Fe2O3 is achieved in α-Fe2O3/Pt heterostructures by a terahertz wave pulse, and the switching capability is consistent with the current pulse-induced switching counterpart. The temperature variation during the terahertz pulse is simulated by finite element simulation analysis, for extreme (∼1.5 ps) short terahertz pulses, the thermal effect can be negligible and the mechanism responsible for the terahertz pulse-induced antiferromagnetic switching points to the dampinglike spin–orbit torque. Our finding paves the way for the antiferromagnet/heavy metal bilayers for ultrahigh density memories and high-frequency devices up to terahertz operation.