A comparative DMFT study of the eg-orbital Hubbard model in thin films

Abstract

Heterostructures of transition-metal oxides emerged as a new route to engineer electronic systems with desired functionalities. Motivated by these developments, we study a two-orbital Hubbard model in a thin-film geometry confined along the cubic [001] direction using the dynamical mean-field theory. We contrast the results of two approximate impurity solvers (exact diagonalization and one-crossing approximation) to the results of the numerically exact continuous-time quantum Monte Carlo solver. Consistent with earlier studies, we find that the one-crossing approximation performs well in the insulating regime, while the advantage of the exact-diagonalization based solver is more pronounced in the metallic regime. We then investigate various aspects of strongly correlated eg-orbital systems in thin film geometries. In particular, we show how the interfacial orbital polarization dies off quickly a few layers from the interface and how the film thickness affects the location of the interaction-driven Mott transition. In addition, we explore the changes in the electronic structure with varying carrier concentration and identify large variations of the orbital polarization in the strongly correlated regime.

11 pages, 11 figures

References in corpus (21)

• Continuous-time Monte Carlo methods for quantum impurity models
• Hybridization expansion impurity solver: General formulation and application to Kondo lattice and two-orbital models
• Orbital order and possible superconductivity in LaNiO3/LaMO3 superlattices
• Spin freezing transition and non-Fermi-liquid self-energy in a 3-orbital model
• Truncated Configuration Interaction expansions as solvers for correlated quantum impurity models and dynamical mean field theory
• Strain and composition dependence of the orbital polarization in nickelate superlattices
• Substrate coherency-driven octahedral rotations in perovskite oxide films
• Conserved quantities of SU(2)-invariant interactions for correlated fermions and the advantages for quantum Monte Carlo simulations
• Bold Line Diagrammatic Monte Carlo Method: General formulation and application to expansion around the Non-Crossing Approximation
• Chemical control of orbital polarization in artificially structured transition-metal oxides: La2NiXO6 (X=B, Al, Ga, In) from first principles
• Electronic structure of (LaNiO${}_3$)${}_2$/(LaAlO${}_3$)${}_N$ heterostructures grown along [111]
• Cellular Dynamical Mean Field Theory for the 1D Extended Hubbard Model
• Topological phases in layered pyrochlore oxide thin films along the [111] direction
• Magnetic and Superconducting Ordering at LaAlO3/SrTiO3 Interfaces
• The Mott insulator LaTiO_3 in heterostructures with SrTiO_3 is metallic
• Lattice distortion effects on topological phases in (LaNiO${}_3$)${}_2$/(LaAlO${}_3$)${}_N$ heterostructures grown along the [111] direction
• Effective crystal field and Fermi surface topology: a comparison of d- and dp-orbital models
• Strongly renormalized quasi-two-dimensional electron gas in a heterostructure with correlation effects
• Ab-initio Low-Energy Model of Transition-Metal-Oxide Heterostructure LaAlO3/SrTiO3
• Aspects of metallic low-temperature transport in Mott-insulator/ band-insulator superlattices: optical conductivity and thermoelectricity
• Sum rule violation in self-consistent hybridization expansions

Cited by in corpus (5)

• Two-site fluctuations and multipolar superexchange interactions in strongly correlated systems
• Correlation effects in pyrochlore iridate thin films grown along the $[111]$ direction
• Reliability of the one-crossing approximation in describing the Mott transition
• Suppression of the Mott insulating phase in the particle-hole asymmetric Hubbard model
• Characterizing Featureless Mott Insulating State by Quasiparticle Interferences - A Dynamical Mean Field Theory Prospect