In Sr2IrO4 and Sr3Ir2O7, correlations, magnetism and spin-orbit coupling compete on similar energy scales, creating a new context to study metal-insulator transitions (MIT). We use here Angle-Resolved photoemission to investigate the MIT as a function of hole and electron doping in Sr3Ir2O7, obtained respectively by Ir/Rh and Sr/La substitutions. We show that there is a clear reduction as a function of doping of the gap between a lower and upper band on both sides of the Fermi level, from 0.2eV to 0.05eV. Although these two bands have a counterpart in band structure calculations, they are characterized by a very different degree of coherence. The upper band exhibits clear quasiparticle peaks, while the lower band is very broad and loses weight as a function of doping. Moreover, their ARPES spectral weights obey different periodicities, reinforcing the idea of their different nature. We argue that a very similar situation occurs in Sr2IrO4 and conclude that the physics of the two families is essentially the same.
@article{arxiv.1810.04092,
title = {Coherent and incoherent bands in La and Rh doped Sr3Ir2O7},
author = {V. Brouet and L. Serrier-Garcia and A. Louat and L. Fruchter and F. Bertran and P. Le Fevre and J. Rault and A Forget and D. Colson},
journal= {arXiv preprint arXiv:1810.04092},
year = {2018}
}