Correlated excitonic signatures of individual van der Waals NiPS3 antiferromagnet nanoflakes

Composite quasi-particles with emergent functionalities in spintronic and quantum information science can be realized in correlated materials due to entangled charge, spin, orbital, and lattice degrees of freedom. Here we show that by reducing the lateral dimension of correlated antiferromagnet NiPS3 flakes to tens of nanometers and thickness to less than ten nanometers, we can switch-off the bulk spin–orbit entangled exciton in the near-infrared (1.47 eV) and activate visible-range (1.8–2.2 eV) transitions. These ultra-sharp lines (