Sign-Free Determinant Quantum Monte Carlo Study of Excitonic Density Orders in a Two-Orbital Hubbard-Kanamori Model

Abstract

While excitonic instabilities in multiorbital systems recently have come under scrutiny in a variety of transition-metal compounds, understanding emergence of these instabilities from strong electronic interactions has remained a challenge. Here, we present a sign-problem-free determinant quantum Monte Carlo study of excitonic density orders in a half-filled two-orbital Hubbard-Kanamori model with broken orbital degeneracy, which accounts for the role of Hund's coupling in transition-metal compounds. For strong inverted (negative) Hund's exchange, we find numerical evidence for the emergence of excitonic density order, with competition between anti-ferro-orbital order and $\mathbf{Q}=(\pi ,\pi )$ excitonic density order as a function of orbital splitting and Hund's coupling. While inverted Hund's coupling stabilizes a spin-singlet excitonic density phase for weak orbital splitting, positive Hund's coupling favors a spin-triplet excitonic density phase.

References in corpus (13)

• Orbital-Selective Mott transition out of band degeneracy lifting
• Orbital selective Mott transition in multi-band systems: slave-spin representation and dynamical mean-field theory
• Analysis of the exciton-exciton interaction in semiconductor quantum wells
• Enhanced Crystal Field Splitting and Orbital Selective Coherence by Strong Correlations in V_2O_3
• Electronic correlations, magnetism and Hund's rule coupling in the ruthenium perovskites SrRuO${}_3$ and CaRuO${}_3$
• Dynamical behavior across the Mott transition of two bands with different bandwidths
• Approaching finite-temperature phase diagrams of strongly correlated materials: a case study for V2O3
• Magnetic and Transport Properties of a Coupled Hubbard Bilayer with Electron and Hole Doping
• Quantum Monte Carlo study for multiorbital systems with preserved spin and orbital rotational symmetries
• Phase diagram of exciton condensate in doped two-band Hubbard model
• Auxiliary Field Quantum Monte Carlo for Multiband Hubbard Models: Controlling the Sign and Phase Problems to Capture Hund's Physics
• Intertwined states at finite temperatures in the Hubbard model
• Exciton formation in strongly correlated electron-hole systems near the semimetal-semiconductor transition

Cited by in corpus (6)

• A New Era of Excitonic Insulators
• Extended regime of coexisting metallic and insulating phases in a two-orbital electronic system
• Low-depth simulations of fermionic systems on square-grid quantum hardware
• Edge magnetism in transition metal dichalcogenide nanoribbons: Mean field theory and determinant quantum Monte Carlo
• Mott-Enhanced Exciton Condensation in a Hubbard bilayer
• Real-space spectral simulation of quantum spin models: Application to generalized Kitaev models