Probing the Neel-Type Antiferromagnetic Order and Coherent Magnon-Exciton Coupling in Van Der Waals VPS3

2D 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 Neel-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 Neel-type AFM order is detected based on the monolayer WSe2/VPS3 heterostructure, which induces an enhanced excitonic state and further certifies the Neel-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.

Automated summary

In this study, the Neel-type antiferromagnetic order in the 2D antiferromagnet VPS3 with out-of-plane anisotropy is experimentally probed. The long-range antiferromagnetic order persists even at the ultrathin limit. Strong interlayer exciton-magnon coupling upon the Neel-type antiferromagnetic order is detected in the monolayer WSe2/VPS3 heterostructure. This discovery provides optical routes to study 2D antiferromagnets and promotes their potential applications in magneto-optics and opto-spintronic devices.