Magnetic Field-Tunable Repulsive Exciton-Exciton Interaction in the van der Waals Antiferromagnet NiPS${}_3$

Kaiyang Huang, Jaena Park, Zhuo Yang +4

Two ultra-narrow absorption peaks around 1.5 eV, which are widely believed to originate from a transition from a spin-orbital entangled triplet to a singlet state, in the two-dimen…