Exciton Selectively Coupled to Magnon Dependent on Spin-Lattice Alignment.

Excitons are the bosonic quasiparticles of electron-hole pairs that can generally be modulated by magnetism through heterostructure engineering, while antiferromagnets cannot generate such modulation fields due to their zero net magnetization. Nevertheless, integrating antiferromagnets with semiconductors remains highly desirable to coordinate exciton emission, offering advantages of negligibly stray fields and faster spin dynamics. However, developing an effective approach to manipulate excitons via antiferromagnetic (AFM) magnons remains challenging. Here, we report magnon-exciton coupling (MEC) in van der Waals (vdW) heterostructures and reveal the distinctive dependence of exciton emission on AFM spin order. Excitons selectively couple with Néel-type antiferromagnets, resulting in a substantial increase in exciton energy. This is attributed to the formation of spin-lattice-aligned channels that facilitate hopping-electron mediated magnon-exciton interaction and valence band splitting. Our results pinpoint the essence of interlayer MEC with respect to AFM spin configuration, providing a new perspective for both elementary excitation modulation and the development of AFM-based opto-spintronics.