Role of spin orbit coupling and electron correlation in the ground state properties of 5d electronic states

TL;DR

This study investigates the interplay of spin-orbit coupling and electron correlation in 5d transition metal oxides, specifically Y2Ir2O7, revealing that electron correlation plays a more significant role than spin-orbit interaction in its ground state.

Contribution

The paper challenges the common assumption that spin-orbit interaction dominates in 5d oxides, showing electron correlation is crucial for understanding Y2Ir2O7's properties.

Findings

Spin-orbit interaction has a marginal effect on Y2Ir2O7's ground state.

Strong electron correlation is necessary to match experimental spectra.

Y2Ir2O7's properties are not solely determined by spin-orbit coupling.

Abstract

Electron correlation strength is predicted to be weak in 5d transition metal oxides and hence, various anomalous electronic properties observed in these systems are often attributed to the large spin-orbit interaction strength. Employing first principles approaches, we studied the electronic structure of Y2Ir2O7, which is insulating and exhibits ferromagnetic phase below 150 K. The results reveal breakdown of both the above paradigms. The role of spin-orbit interaction is found to be marginal in determining the ground state properties of Y2Ir2O7. A large electron correlation strength is required to derive the experimental bulk spectrum that is consistent with the bulk properties.