RQMP Get-Together

Modelling iridates: from multiorbital magnetism towards possible superconductivity

Lena Engström

McGill / Université de Montréal

Strontium iridates have been predicted to be a new family of superconducting compounds [1]. However, no superconductivity has been confirmed experimentally [2]. From a theoretical point of view this indicates that the simplest iridate model fails to capture some important properties of the system. In the undoped iridates, an effective pseudospin order arises as the dominant state from an underlying strongly spin orbit coupled multiorbital order. In this talk I will go through the attempts to model the iridate compound Sr₂IrO₄, considering the effective model and going beyond it. To explore how the system could be tuned to be a more favorable environment for superconductivity I will present results from a comprehensive mean field study of the magnetic order. By sweeping through a larger parameter space, including a variation of interaction parameters, an external magnetic field, and an epitaxial strain, we observe phase transitions into promising new regimes.

[1] F. Wang and T. Senthil, Phys. Rev. Lett. 106, 136402 (2011)
[2] Y. K. Kim, N. H. Sung, J. D. Denlinger, and B. J. Kim, Nature Physics 12, 37 (2016)