Advanced First-Principle Modeling of RelativisticRuddlesden—Popper Strontium Iridates

Author(s)
Peitao Liu, Cesare Franchini
Abstract

In this review, we provide a survey of the application of advanced first-principle methods on the theoretical modeling and understanding of novel electronic, optical, and magnetic properties of the spin-orbit coupled Ruddlesden–Popper series of iridates Srn+1 IrnO3n+1 (n = 1, 2, and ∞). After a brief description of the basic aspects of the adopted methods (noncollinear local spin density approximation plus an on-site Coulomb interaction (LSDA+U), constrained random phase approximation (cRPA), GW, and Bethe–Salpeter equation (BSE)), we present and discuss select results. We show that a detailed phase diagrams of the metal–insulator transition and magnetic phase transition can be constructed by inspecting the evolution of electronic and magnetic properties as a function of Hubbard U, spin–orbit coupling (SOC) strength, and dimensionality n, which provide clear evidence for the crucial role played by SOC and U in establishing a relativistic (Dirac) Mott–Hubbard insulating state in Sr2IrO4 and Sr3 Ir2O7. To characterize the ground-state phases, we quantify the most relevant energy scales fully ab initio—crystal field energy, Hubbard U, and SOC constant of three compounds—and discuss the quasiparticle band structures in detail by comparing GW and LSDA+U data. We examine the different magnetic ground states of structurally similar n = 1 and n = 2 compounds and clarify that the origin of the in-plane canted antiferromagnetic (AFM) state of Sr2 IrO4 arises from competition between isotropic exchange and Dzyaloshinskii–Moriya (DM) interactions whereas the collinear AFM state of Sr3 Ir2O7 is due to strong interlayer magnetic coupling. Finally, we report the dimensionality controlled metal–insulator transition across the series by computing their optical transitions and conductivity spectra at the GW+BSE level from the the quasi two-dimensional insulating n = 1 and 2 phases to the three-dimensional metallic n = ∞ phase.

Organisation(s)
Computational Materials Physics
External organisation(s)
Università degli Studi di Bologna
Journal
Applied Sciences (Switzerland)
Volume
11
No. of pages
26
ISSN
2076-3417
DOI
https://doi.org/10.3390/app11062527
Publication date
03-2021
Peer reviewed
Yes
Austrian Fields of Science 2012
103018 Materials physics, 103015 Condensed matter
Keywords
ASJC Scopus subject areas
Materials Science(all), Instrumentation, Engineering(all), Process Chemistry and Technology, Computer Science Applications, Fluid Flow and Transfer Processes
Portal url
https://ucris.univie.ac.at/portal/en/publications/advanced-firstprinciple-modeling-of-relativisticruddlesdenpopper-strontium-iridates(8ebbd922-19b7-47b4-90cf-2a320dc7aead).html