Dispersion of low-energy optical excitations in NiPS${}_3$ explained by singlet polaron theory

I. J. Hamad, C. S. Helman, A. E. Feiguin +2

Optical and resonant inelastic X-ray scattering (RIXS) experiments in the van der Waals antiferromagnet NiPS${}_3$ have revealed narrow excitonic resonances near 1.5 eV whose microsc…