Illustration from Scientific Research

Schematic of exciton–exciton interactions in CrSBr mediated by magnons. Under a finite magnetic field applied perpendicular to the flake, the magnetization vectors of the two sublattices (that is, neighbouring layers) tilt with the angle θ between them. Owing to the exciton–magnon coupling in noncollinear configurations, this angle depends on the exciton density. The inset shows the atomic arrangements in CrSBr crystals projected on the b – c plane, along with spin alignments (as indicated by the arrows) at different magnetic fields, including AFM and FM orders. e, electron; h, hole.

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