Cavity Probes and Control of Antiferromagnetic Fluctuations in a Mott Insulator*

We present a mechanism for coupling the electromagnetic field of a THz cavity to the antiferromagnetic order in a simplified model of an undoped cuprate Mott insulator. In addition to the direct magnetic-dipole coupling between spins and the magnetic component of the near-field radiation, we also consider a more elaborate magnetoelectric coupling which couples various spin-exchange processes to the electric field. We show how these terms can lead to the formation of Neel magnon-polariton resonances, as well as allow for the optical parametric driving of spin-waves. We identify clear experimental signatures to look for in a proposed setup. Finally, we conclude by speculating about the fate of charge carriers doped into the system in the presence of our coupling scheme.