Authors: Jian Liu, University of TennesseeCorrelation-topology Interplay in pseudospin-half square-lattice in artificial iridate superlattice.

Fundamental interests arise in systems where both electronic correlation and electronic topology play significant roles. Their interplay could provide not only new routes to unresolved problems but also opportunities for stabilizing novel quantum states. However, a key challenge in this extensive and largely unexplored regime is the fact that topological properties, such as Berry phase, concern extended electronic wavefunctions described in momentum space while electrons are localized in real space in correlated systems. This dilemma calls for toy-model materials where phenomena driven by the topology-correlation interplay can be captured and controlled. In this talk, I will discuss our recent work on experimental realization of artificial iridate superlattices that simulate the single-orbital square-lattice Hubbard Hamiltonian with engineered complex hopping. While the correlated pseudospin-half electrons have an antiferromagnetic Mott insulating ground state, their intermediate coupling strength allows significant longitudinal spin fluctuations, which manifest as anomalous magnetoresistance and anomalous Hall effect through the SU(2) symmetry-preserving and breaking components of the complex hopping, respectively. The latter also leads to an exceptionally large Ising anisotropy captured as a giant magnon gap beyond the superexchange approach. These unusual phenomena of a 2D Mott insulator highlight the rich interplay of electronic topology and electronic correlation in the intermediate-coupling regime.