F39: 5d/4d Transition Metal Systems I

Tue. March 7, 8:48 a.m. – 9:00 a.m. PST

Room 231

The iridates offer a unique environment of strong interactions and spin-orbit coupling. Sr₂IrO₄ is a spin-orbit coupled antiferromagnet. Under electron doping it is predicted to have a, yet unconfirmed, superconducting order. However, the magnetism remains strong for chemical doping. We model compressive strain as an additional knob to tune correlations in this multi-orbital compound. The magnetism in Sr2IrO4 has been shown to be sensitive to the lattice geometry. As the lattice is modified by a compressive strain, magnetism is suppressed and the Fermi surface topology changes. By modelling a strain-dependent effective interaction via the random phase approximation, the found phase diagram under doping and strain has superconducting regions. A cuprate-like d-wave superconductivity is favored under strain. In addition, several multi-band orders can be favored when tuning the interaction parameters and band structure. Both an s_+--wave and an odd parity order can be present. As the strain is increased the spin-orbit coupled nature of the compound comes into question as correlations in spin and pseudospin channels can compete. We discuss regimes where strain and doping are more likely to result in superconductivity.