Optical Signature of a Crossover from Mott- to Slater-type Gap in Sr${}_2$Ir${}_{1-x}$Rh${}_x$O${}_4$

B. Xu, P. Marsik, E. Sheveleva +5

With optical spectroscopy we provide evidence that the insulator-metal transition in Sr${}_2$Ir${}_{1-x}$Rh${}_x$O${}_4$ occurs close to a crossover from the Mott- to the Slater-type.…