Spin-orbit coupling controlled $J=3/2$ electronic ground state in 5$d^{3}$ oxides

TL;DR

This study uncovers a novel spin-orbit entangled J=3/2 ground state in 5d^3 oxides, achieved through resonant inelastic x-ray scattering and an intermediate coupling model, expanding understanding of spin-orbit physics in complex oxides.

Contribution

The paper introduces an intermediate coupling approach that accurately describes the J=3/2 ground state in 5d^3 oxides, revealing a new class of spin-orbit entangled states.

Findings

Identification of a J=3/2 ground state in 5d^3 oxides

Validation of the intermediate coupling model for these materials

Discovery of diverse spin-orbit controlled ground states in 5d systems

Abstract

Entanglement of spin and orbital degrees of freedom drives the formation of novel quantum and topological physical states. Discovering new spin-orbit entangled ground states and emergent phases of matter requires both experimentally probing the relevant energy scales and applying suitable theoretical models. Here we report resonant inelastic x-ray scattering measurements of the transition metal oxides Ca$_3$LiOsO$_6$ and Ba$_2$YOsO$_6$. We invoke an intermediate coupling approach that incorporates both spin-orbit coupling and electron-electron interactions on an even footing and reveal the ground state of $5d^3$ based compounds, which has remained elusive in previously applied models, is a novel spin-orbit entangled J=3/2 electronic ground state. This work reveals the hidden diversity of spin-orbit controlled ground states in 5d systems and introduces a new arena in the search for spin-orbit controlled phases of matter.