In-gap band in the one-dimensional two-orbital Kanamori-Hubbard model with inter-orbital Coulomb interaction

Autor: N. Aucar Boidi, H. Fernández García, Y. Núñez-Fernández, K. Hallberg
Přispěvatelé: Comisión Nacional de Energía Atómica [ARGENTINA] (CNEA), Laboratory of Quantum Theory (GT), PHotonique, ELectronique et Ingénierie QuantiqueS (PHELIQS), Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Fondamentale (CEA) (DRF (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)-Institut de Recherche Interdisciplinaire de Grenoble (IRIG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Grenoble Alpes (UGA)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Physical review research
Physical Review Research
Physical Review Research, 2021, 3 (4), pp.043213. ⟨10.1103/PhysRevResearch.3.043213⟩
ISSN: 2643-1564
Popis: We study the electronic spectral properties at zero temperature of the one-dimensional (1D) version of the degenerate two-orbital Kanamori Hubbard model (KHM), one of the well established frameworks to study transition metal compounds, using state-of-the-art numerical techniques based on the Density Matrix Renormalization Group. While the system is Mott insulating for the half-filled case, as expected for an interacting 1D system, we find interesting and rich structures in the single-particle density of states (DOS) for the hole-doped system. In particular, we find the existence of in-gap states which are pulled down to lower energies from the upper Hubbard band (UHB) with increasing the inter-orbital Coulomb interaction $V$. We analyze the composition of the DOS by projecting it onto different local excitations and we observe that for large dopings these in-gap excitations are formed mainly by inter-orbital holon-doublon (HD) states and their energies follow approximately the HD states in the atomic limit. We observe that the Hund interaction $J$ increases the width of the in-gap band, as expected from the two-particle fluctuations in the Hamiltonian. The observation of a finite density of states within the gap between the Hubbard bands for this extended 1D model indicates that these systems present a rich excitation spectra which could help us understand the microscopic physics behind multi-orbital compounds.
Databáze: OpenAIRE