Pseudogap and electronic structure of electron-doped Sr$_2$IrO$_4$

TL;DR

This paper theoretically investigates how electron doping affects the electronic structure of Sr$_2$IrO$_4$, revealing a rapid Mott gap collapse, momentum-space differentiation, and a pseudogap related to spin correlations, aligning well with experiments.

Contribution

It provides a detailed theoretical analysis of doping-induced electronic structure changes in Sr$_2$IrO$_4$, highlighting the pseudogap's origin and evolution within a dynamical mean-field theory framework.

Findings

Rapid collapse of the Mott gap upon doping

Formation of Fermi surface pockets around $(rac{ ext{pi}}{2},rac{ ext{pi}}{2})$

Persistence of spectral intensity modulation at higher doping levels

Abstract

We present a theoretical investigation of the effects of correlations on the electronic structure of the Mott insulator Sr$_2$IrO$_4$ upon electron doping. A rapid collapse of the Mott gap upon doping is found, and the electronic structure displays a strong momentum-space differentiation at low doping level: The Fermi surface consists of pockets centered around $(\pi/2,\pi/2)$, while a pseudogap opens near $(\pi,0)$. Its physical origin is shown to be related to short-range spin correlations. The pseudogap closes upon increasing doping, but a differentiated regime characterized by a modulation of the spectral intensity along the Fermi surface persists to higher doping levels. These results, obtained within the cellular dynamical mean-field theory framework, are discussed in comparison to recent photoemission experiments and an overall good agreement is found.