Key points are not available for this paper at this time.
In the quest for exotic phases of matter due to the interplay of various interactions, iridates hosting a spin-orbit entangled j₄₅₅=1/2 ground state have been in the spotlight in recent years. Also in view of parallels with the low-energy physics of high-temperature superconducting cuprates, the validity of a single- or few-band picture in terms of the j₄₅₅ states is key. However, in particular, for its structurally simple member Ba₂IrO₄, such a systematic construction and subsequent analysis of minimal low-energy models are still missing. Here we show by means of a combination of different ab initio techniques with dynamical mean-field theory that a three-band model in terms of Ir-j₄₅₅ states fully retains the low-energy physics of the system as compared to a full Ir-5d model. Providing a detailed study of the three-band model in terms of spin-orbit coupling, Hund's coupling, and Coulomb interactions, we map out a rich phase diagram and identify a region of an effective one-band metal-insulator transition relevant to Ba₂IrO₄. Compared to available angle-resolved photoemission spectra, we find good agreement of salient aspects of the calculated spectral function and identify features which require the inclusion of nonlocal fluctuations. In a broader context, we envisage the three- and five-band models developed in this paper to be relevant for the study of doped Ba₂IrO₄ and to further clarify the similarities and differences with cuprates.
Cassol et al. (Fri,) studied this question.