Probing the Néel‐Type Antiferromagnetic Order and Coherent Magnon–Exciton Coupling in Van Der Waals VPS3

Abstract

Abstract2D van der Waals (vdW) antiferromagnets have received intensive attention due to their terahertz resonance, multilevel magnetic‐order states, and ultrafast spin dynamics. However, accurately identifying their magnetic configuration still remains a challenge owing to the lack of net magnetization and insensitivity to external fields. In this work, the Néel‐type antiferromagnetic (AFM) order in 2D antiferromagnet VPS3 with the out‐of‐plane anisotropy, which is demonstrated by the temperature‐dependent spin–phonon coupling and second‐harmonic generation (SHG), is experimentally probed. This long‐range AFM order even persists at the ultrathin limit. Furthermore, strong interlayer exciton–magnon coupling (EMC) upon the Néel‐type AFM order is detected based on the monolayer WSe2/VPS3 heterostructure, which induces an enhanced excitonic state and further certifies the Néel‐type AFM order of VPS3. The discovery provides optical routes as the novel platform to study 2D antiferromagnets and promotes their potential applications in magneto‐optics and opto‐spintronic devices.