Low-energy interband Kondo bound states in orbital-selective Mott phases

Abstract

Low-energy excitations in correlated electron systems may show intricate behaviors and provide essential insights into the dynamics of quantum states and phase transitions. Here, we study a typical half-filled two-orbital Hubbard model featuring the so-called holon-doublon (HD) low-energy excitations in the orbital-selective Mott phase (OSMP), where the principal form of the low-energy excitations has been considered to be a HD bound state. We employ standard single-site dynamical mean-field theory (DMFT), using NORG as an improved impurity solver to calculate the spectral functions at zero temperature. We show that the HD bound state gives an incomplete or even wrong picture for the low-energy excitations. Instead, the excitations are composed of a Kondo-like state in the wide band and a doublon in the narrow band, termed as inter-band Kondo-like (IBK) bound states. Remarkably, we find that, as the bandwidths of the two bands approach each other, anomalous IBK bound-state excitations appear in the metallic {\em wide} band. Our study provides a new picture for the low-energy excitations in the OSMP.

8 pages, 7 figures

References in corpus (21)

• The Kernel Polynomial Method
• Orbital-Selective Mott transition out of band degeneracy lifting
• Hund's coupling key role in multi-orbital correlations
• Correlation Effects and Concomitant Two-Orbital $s_{\pm }$-Wave Superconductivity in La${}_3$Ni${}_2$O${}_7$ under High Pressure
• Orbital-selective Mott transitions: Heavy fermions and beyond
• Dynamical behavior across the Mott transition of two bands with different bandwidths
• Correlation-Driven Electronic Reconstruction in FeTe${}_{1-x}$Se${}_x$
• Orbital-selective Mott phase in multiorbital models for iron pnictides and chalcogenides
• Orbital-selective altermagnetism and correlation-enhanced spin-splitting in transition metal oxides
• Natural Orbitals Renormalization Group Approach to the Two-Impurity Kondo Critical Point
• Microscopic Theory of Superconducting Phase Diagram in Infinite-Layer Nickelates
• Analytical slave-spin mean-field approach to orbital selective Mott insulators
• Orbital Selective Mott Transition Effects and Non-Trivial Topology of Iron Chalcogenide
• Orbital-selective Mott phase and non-Fermi liquid in FePS${}_3$
• Non-Fermi liquid and antiferromagnetic correlations with hole doping in the bilayer two-orbital Hubbard model of La${}_3$Ni${}_2$O${}_7$ at zero temperature
• DFT+DMFT study of correlated electronic structure in the monolayer-trilayer phase of La${}_3$Ni${}_2$O${}_7$
• In-gap band in the one-dimensional two-orbital Kanamori-Hubbard model with inter-orbital Coulomb interaction
• An Anderson impurity interacting with the helical edge states in a quantum spin Hall insulator
• Hund bands in spectra of multiorbital systems
• Orbital-selective metal skin induced by alkali-metal-dosing Mott-insulating Ca${}_2$RuO${}_4$
• Unconventional correlated metallic behavior due to interorbital Coulomb interaction