Related papers: Hund physics landscape of two-orbital system
Strong electronic correlations, emerging from the parent Mott insulator phase, are key to copper-based high temperature superconductivity (HTS). By contrast, the parent phase of iron-based HTS is never a correlated insulator. But this…
Superconductivity and nematicity coexist in the phase diagram of many correlated systems, including iron-based superconductors. We investigate how Hund-driven correlations reshape boson-mediated superconductivity in a multiorbital nematic…
Near a Mott transition, strong electron correlations may enhance Cooper pairing. This is demonstrated in the Dynamical Mean Field Theory solution of a twofold-orbital degenerate Hubbard model with inverted Hund's rules on-site exchange,…
We explore the transition to a charge-disproportionated insulating phase in a five-orbital cubic tight-binding model applicable to transition-metal perovskites with a formal $d^4$ occupation of the transition-metal cation, such as ferrates…
Since the discovery of superconductivity in infinite-layer nickelates RNiO$_2$ (R=La, Pr, Nd), great research efforts have been paid to unveil its underlying superconducting mechanism. However, the physical origin of the intriguing…
The recently discovered superconductivity in Nd$_{1-x}$Sr$_x$NiO$_2$ provides a new opportunity for studying strongly correlated unconventional superconductivity. The single-hole Ni$^+$ ($3d^9$) configuration in the parent compound…
The one-dimensional SU(4) Hubbard model perturbed by Hund coupling is studied, away from half-filling, by means of renormalization group and bosonization methods. A spectral gap is always present in the spin-orbital sector irrespective of…
A model of superconductivity in layered high-temperature superconducting cuprates is proposed, based on the extended saddle point singularities in the electron spectrum, weak screening of the Coulomb interaction and phonon-mediated…
We point out the generic competition between the Hund's coupling and the spin-orbit coupling in correlated materials, and this competition leads to an electronic dilemma between the Hund's metal and the relativistic insulators. Hund's…
We study the doping-driven Mott metal-insulator transition for multi-orbital Hubbard models with Hund's exchange coupling at finite temperatures. As in the single-orbital Hubbard model, the transition is of first-order within dynamical mean…
The pairing symmetry in infinite-layer nickelate superconductors has been an intriguing problem under heated debates. In this work, we study a two-orbital Hubbard model with one strongly correlated $3d$ orbital and one more itinerant $5d$…
The discovery of high-temperature superconductivity in bilayer nickelate La$_{3}$Ni$_{2}$O$_{7}$ necessitates a minimal theoretical model that unifies the superconducting phase with the spin-density-wave (SDW) phase without external…
Recent advances in the field of quantum Monte Carlo simulations for impurity problems allow --within dynamical mean field theory-- for a more thorough investigation of the two-band Hubbard model with narrow/wide band and SU(2)-symmetric…
This paper is a brief review of our recent studies concerning on magnetism and electronic states of lattice systems with Hund coupling. First we examined the effectiveness of the Hund coupling in realizing ferromagnetism in the doubly…
We study the Mott metal-insulator transition in the two-band Hubbard model with different hopping amplitudes $t_1$ and $t_2$ for the two orbitals on the two-dimensional square lattice by using {\it non-magnetic} variational wave functions,…
We evaluate numerically several superconducting correlation functions in a generalized $t-J$ model derived for hole-doped CuO$_2$ planes. The model includes a three-site term $t''$ similar to that obtained in the large $U$ limit of the…
Motivated by the recently discovered high $T_c$ nickelate superconductor $\mathrm{La_3Ni_2O_7}$, we investigate superconductivity in a two dimensional Hubbard model on square lattice that consists of two layers of hybridizing $d_{x^2-y^2}$…
The interplay among orbital-selective Mott physics, Hund's coupling, tunable structural motifs, and Kondo-like scattering establishes a compelling paradigm for understanding and engineering correlated multi-orbital systems, as vividly…
We report a determinant quantum Monte Carlo study of a two-band model, inspired by infinite-layer nickelates, focusing on the influence of interlayer hybridization between $3d_{x^2-y^2}$ orbitals derived from Ni (or Ni and O) in one layer…
We study a two-band Hubbard model using the dynamical mean-field theory combined with the exact diagonalization method. At the electron density $n=2$, a transition from a band-insulator to a correlated semimetal occurs when the on-site…