Spin–orbit-controlled correlation physics and orbital-selective electronic transitions in uranium monoxide revealed by many-body calculations

Abstract

We present a comprehensive study of the temperature-dependent electronic structure in uranium monoxide (UO) using the local density approximation (LDA) combined with dynamical mean-field theory (LDA + DMFT). Our calculations reveal orbital-selective electronic transitions driven by relativistic spin–orbit coupling, leading to metallic 5f_5/2 states and insulating 5f_7/2 states. These transitions are robust against thermal perturbations, suggesting a many-body protection mechanism. We observe significant quasiparticle renormalization and non-Fermi liquid signatures near the Fermi level. Thermal and lattice effects on 5f electron localization and hybridization are decoupled, with lattice expansion modulating hybridization energetics and temperature variations affecting dynamic screening. Our findings establish UO as a prototype material for studying spin–orbit-dominated correlation physics.