Spin correlated electronic state on the surface of a spin-orbit Mott system (Layered Iridates)

Understand

Novel phases of two dimensional electron systems resulting from new surface or interface modified electronic structures have generated significant interest in material science.

• We utilize photoemission spectroscopy to show that the near-surface electronic structure of a bulk insulating iridate Sr$_3$Ir$_2$O$_7$ lying near metal-Mott insulator transition exhibit weak metallicity signified by finite electronic spectral weight at the Fermi level.
• The surface electrons exhibit a unique spin structure resulting from an interplay of spin-orbit, Coulomb interaction and surface quantum magnetism, distinct from a topological insulator state.
• Our results suggest the experimental realization of a novel quasi two dimensional interacting electron surface ground state, opening the door for exotic quantum entanglement and transport phenomena in iridate-based oxide devices.