Related papers: Orbital Frustration and Emergent Flat Bands
We develop a strong coupling approach towards quantum magnetism in Mott insulators for Wannier obstructed bands. Despite the lack of Wannier orbitals, electrons can still singly occupy a set of exponentially-localized but nonorthogonal…
The interplay between spin and orbital degrees of freedom gives rise to a variety of emergent phases in correlated 4d and 5d transition-metal systems. Strong spin-orbit coupling (SOC) significantly alters Jahn-Teller (JT) physics, often…
Hyperhoneycomb iridate $\beta$-Li$_2$IrO$_3$ is a three-dimensional analogue of two-dimensional honeycomb iridates, such as $\alpha$-Li$_2$IrO$_3$, which recently appeared as another playground for the physics of Kitaev-type spin liquid.…
By employing determinant quantum Monte Carlo simulations, we investigate a checkerboard lattice with next-nearest-neighbor hopping $t'$ as the frustration-control parameter, which exhibits an energetically partial flat-band in the system.…
A $t_{2g}^5$ system with a honeycomb lattice structure such as Na$_2$IrO$_3$ was firstly proposed as a topological insulator even though Na$_2$IrO$_3$ and its isostructural materials in nature have been turned out to be a Mott insulator…
The Lieb lattice possesses three bands and with intrinsic spin orbit coupling $\lambda$, supports topologically non-trivial band insulating phases. At half filling the lower band is fully filled, while the upper band is empty. The chemical…
Motivated by the recent progress in realizing and controlling extended Bose-Hubbard systems using excitonic or atomic devices, the present Letter theoretically investigates the case of a two-band Bose-Hubbard chain with nearest-neighbor…
In this short review, which is based on the works published between 2011 and 2016, we discuss the problem of the propagation of a collective orbital excitation (orbiton) created in the Mott insulating and antiferromagnetic ground state. On…
Electronic flat bands represent a paradigmatic platform to realize strongly correlated matter due to their associated divergent density of states. In common instances, including electron-electron interactions leads to magnetic instabilities…
The delicate interplay among the complex intra-/inter-layer electron-electron and electron-lattice interactions is the fundamental prerequisite of these exotic quantum states, such as superconductivity, nematic order, and checkerboard…
In the quest of why there should be a single transition temperature in a multi-gapped system like Fe-based materials we use two band model for simplicity. The model comprises of spin density wave (SDW), orbital density wave (ODW) arising…
The bilayer Hubbard model with an intra-layer hopping $t$ and an inter-layer hopping $t_\perp$ provides an interesting testing ground for several aspects of what has been called unconventional superconductivity. One can study the type of…
A large class of correlated quantum materials feature strong Hund's coupling. Yet cold-atom quantum simulators have so far focused primarily on single-orbital Fermi-Hubbard systems near a Mott insulator. Here we show that repulsively…
We provide analytical and numerical solution of the two band fermion model with on-site Coulomb at half filling. In limiting cases for generate bands and one flat band, the model reduces to the Hubbard and Falicov-Kimball models,…
We investigate the influence of an unoccupied band on the transport properties of a strongly correlated electron system. For that purpose, additional orbitals are coupled to a Hubbard model via hybridization. The filling is one electron per…
We study the effects of an orbital magnetic field on the Mott metal-insulator transition in the Hubbard-Hofstadter model. We demonstrate that sufficiently large magnetic fields induce a Mott insulator-to-metal phase transition supporting…
We study the resonating valence bond (RVB) theory of the Hubbard-Heisenberg model on the half-filled anisotropic triangular lattice. Varying the frustration changes the wavevector of maximum spin correlation in the Mott insulating phase.…
Moir\'e materials with flat electronic bands provide a highly controllable quantum system for studies of strong-correlation physics and topology. In particular, angle-aligned heterobilayers of semiconducting transition metal dichalcogenides…
We study, within the fluctuation exchange approximation, the spin-fluctuation-mediated superconductivity in Hubbard-type models possessing electron and hole bands, and compare them with a model on a square lattice with a large Fermi…
We consider an electronic model for realizing the Spin Bose-metal (SBM) phase on a 2-leg triangular strip --a spin liquid phase found by D. N. Sheng et al [Phys. Rev. B {\bf 79}, 205112 (2009)] in a spin-1/2 model with ring exchanges. The…