Related papers: The Hubbard model on a triangular lattice -- pseud…
Using numerical techniques we study the spectral function $A(k,\omega)$ of a spin-fermion model for cuprates in the regime where magnetic and charge domains (stripes) are developed upon hole-doping. From $A(k,\omega)$ we study the…
The pseudogap phenomena in High-$T_{{\rm c}}$ cuprates are investigated on the basis of the Hubbard model which includes only the on-site repulsive interaction $U$. We consider the pairing scenario for the pseudogap. The pseudogap arises…
We report on numerically exact determinantal quantum Monte Carlo simulations of the onset of spin-density wave (SDW) order in itinerant electron systems captured by a sign-problem-free two-dimensional lattice model. Extensive measurements…
Using recently developed quantum SU(2)xU(1) rotor approach, that provides a self-consistent treatment of the antiferromagnetic state we have performed electronic spectral function calculations for the Hubbard model on the square lattice.…
We investigate the spectral properties of the doped ${t-t'}$ Hubbard model with parameters typical for high-temperature cuprate superconductors. Our approach is based on a novel strong-coupling Green's function expansion around a reference…
We re-consider the self-energy of a nodal (Dirac) fermion in a 2D d-wave superconductor. A conventional belief is that Im \Sigma (\omega, T) \sim max (\omega^3, T^3). We show that \Sigma (\omega, k, T) for k along the nodal direction is…
It is shown that the energy $(\varepsilon)$ and momentum $(k)$ dependences of the electron self-energy function $ \Sigma (k, \varepsilon + i0) \equiv \Sigma^{R}(k, \varepsilon) $ are, $ {\rm Im} \Sigma^{R} (k, \varepsilon) =…
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…
Single crystals of pristine and 6% Pd-intercalated 2H-TaSe$_2$ have been studied by means of $^{77}$Se nuclear magnetic resonance (NMR). The temperature dependence of the $^{77}$Se spectrum, with an unexpected line narrowing upon Pd…
Focusing on La_{2-x}Sr_{x}CuO_{4}, we study the stripe structure by the self-consistent mean-field theory of the Hubbard model. By introducing the realistic Fermi surface topology, the SDW-gapped insulator is changed to metallic. The…
The celebrated antiferromagnetic phase transition was realized in a most recent optical lattice experiment for 3D fermionic Hubbard model [Shao {\it et al}., Nature {\bf 632}, 267 (2024)]. Despite the great achievement, it was observed that…
At mean-field level the t-J model shows a phase diagram with close analogies to the phase diagram of hole doped cuprates. An order parameter associated with the flux or $d$ charge-density wave ($d$-CDW) phase competes and coexists with…
Fermionic atoms in a large-scale, homogeneous optical lattice provide an ideal quantum simulator for investigating the fermionic Hubbard model, yet achieving this remains challenging. Here, by developing a hybrid potential that integrates a…
High-Tc superconducting materials (HTSC) have anomalous properties such as the pseudo-gap or spin-gap etc., in Hall coefficient, 1/T1T and the density of states etc. First including effects of strong on-site repulsion between d-electrons at…
The effect of doping in the two-dimensional Hubbard model is studied within finite temperature exact diagonalization combined with cluster dynamical mean field theory. By employing a mixed basis involving cluster sites and bath molecular…
We consider the possibility of formation of an unconventional spin density wave (USDW) in quasi-one dimensional electronic systems. In analogy with unconventional superconductivity, we develop a mean field theory of SDW allowing for the…
We study extended Hubbard model on a triangular lattice near doping $x=1/3$, which may be relevant for the recently discovered superconductor Na$_x$CoO$_2 \cdot y$H$_2$O. By generalizing this model to $N$ fermionic species, we formulate a…
By using an extended mean-field theory, we study the phase diagram of the topological Kondo lattice model on the honeycomb lattice at half-filling in which the conduction electrons are described by the Haldane model. Besides the…
Using a recently developed perturbative approach, which considers Hubbard operators as fundamental excitations, we have performed electronic self-energy and spectral function calculations for the $t-J$ model on the square lattice. We have…
The Hubbard model and its extensions are canonical theoretical frameworks for understanding correlated electronic states, including those in high-$T_c$ cuprates. Here, we use state-of-the-art thermal tensor network method to map out the…