Atomic-scale imaging of insulator to metal transition in Ru-doped Sr2IrO4

Layered Iridium-oxides (iridates) have attracted a lot of attention for unconventional electronic phenomena at the intersection of magnetism and strong spin-orbit coupling. Single-layer Sr2IrO4 in particular has been widely studied due to its Jeff=1/2 Mott insulating state and intriguing parallels to high-Tc cuprates. In this talk, I will discuss our scanning tunneling microscopy (STM) and spin-polarized STM experiments on cleaved bulk single crystals of Ru-doped Sr2IrO4. In particular, we study the insulator-to-metal transition in Sr₂Ir_xRu_1-xO₄. We visualize large spatial variations in the local density of states across this transition and explore the connections to the Lifshitz transition. Our experiments provide new atomic-scale insights into the insulator-to-metal transition in heavily Ru-doped iridates.