Single-Shot Laser-Induced Switching of an Exchange Biased Antiferromagnet.

Guo, Zongxia; Wang, Junlin; Malinowski, Gregory; Zhang, Boyu; Zhang, Wei; Wang, Hangtian; Lyu, Chen; Peng, Yi et al. · Adv Mater · 2024

basic_science · Level V

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Abstract

Ultrafast manipulation of magnetic order has challenged the understanding of the fundamental and dynamic properties of magnetic materials. So far single-shot magnetic switching has been limited to ferrimagnetic alloys, multilayers, and designed ferromagnetic (FM) heterostructures. In FM/antiferromagnetic (AFM) bilayers, exchange bias (H<sub>e</sub>) arises from the interfacial exchange coupling between the two layers and reflects the microscopic orientation of the antiferromagnet. Here the possibility of single-shot switching of the antiferromagnet (change of the sign and amplitude of H<sub>e</sub>) with a single femtosecond laser pulse in IrMn/CoGd bilayers is demonstrated. The manipulation is demonstrated in a wide range of fluences for different layer thicknesses and compositions. Atomistic simulations predict ultrafast switching and recovery of the AFM magnetization on a timescale of 2 ps. The results provide the fastest and the most energy-efficient method to set the exchange bias and pave the way to potential applications for ultrafast spintronic devices.