Orbitally-selective Breakdown of the Fermi Liquid and Simultaneous Enhancement of Metallic and Insulating States in Correlated Multi-band Systems with Spin-orbit Coupling

Abstract

We show that spin-orbit coupling (SOC) plays Janus-faced roles on the orbitally-selective Mott transitions in a three-orbital Hubbard model with crystal field splitting at a specific filling of $2/3$, which is a minimal Hamiltonian for ruthenates. While the SOC favors metallic state due to enhancement of orbital hybridization at smaller on-site Coulomb repulsions, it stabilizes the Mott insulating state ascribed to lifting of orbital degeneracies and enhancement of band polarizations at larger electronic interaction. Moreover, an orbitally-selective non-Fermi liquid (OSnFL), where breakdown and retention of the Fermi liquid coexist in different orbitals, emerges between the orbitally-selective Mott phase and the Fermi-liquid state. This novel state can be used to account for the exotic metallic behavior observed in 4$d$ materials, such as Ca${}_{1.8}$Sr${}_{0.2}$RuO${}_4$, Ba${}_2$RuO${}_4$ under strain and Sr${}_2$RuO${}_4$ under uniaxial pressure. We propose that orbitally-selective Kondo breakdown may account for the OSnFL.

12 pages, 8 figures

References in corpus (19)

• Strong electronic correlations from Hund's coupling
• $\alpha$-RuCl3: a Spin-Orbit Assisted Mott Insulator on a Honeycomb Lattice
• Coherence-incoherence crossover in the normal state of iron-oxypnictides and importance of the Hund's rule coupling
• Cluster Dynamical Mean Field Theory of the Mott Transition
• Magnetism and Charge Dynamics in Iron Pnictides
• The coherence-incoherence crossover and the mass-renormalization puzzles in Sr2RuO4
• Orbital-Selective Mott transition out of band degeneracy lifting
• Na2IrO3 as a spin-orbit-assisted antiferromagnetic insulator with a 340 meV gap
• Observation of Temperature-Induced Crossover to an Orbital-Selective Mott Phase in A${}_x$Fe${}_{2-y}$Se${}_2$ (A=K, Rb) Superconductors
• High-spin to low-spin and orbital polarization transitions in multiorbital Mott systems
• Hund's coupling key role in multi-orbital correlations
• Odd-parity triplet superconductivity in multi-orbital materials with strong spin-orbit coupling: applications to doped Sr2IrO4
• Electronic correlations, magnetism and Hund's rule coupling in the ruthenium perovskites SrRuO${}_3$ and CaRuO${}_3$
• Pseudogap and Mott Transition Studied by Cellular Dynamical Mean Field Theory
• Spin-Orbit-Induced Orbital Excitations in Sr2RuO4 and Ca2RuO4: A Resonant Inelastic X-ray Scattering Study
• Observation of spin-orbit excitations and Hund's multiplets in Ca${}_2$RuO${}_4$
• J-freezing and Hund's rules in spin-orbit-coupled multiorbital Hubbard models
• Revealing the Hidden Heavy Fermi Liquid in CaRuO3
• Orbitally selective breakdown of Fermi liquid quasiparticles in Ca${}_{1.8}$Sr${}_{0.2}$RuO${}_4$