Related papers: Superconductivity in the two-dimensional Hubbard m…
We study the dynamics of the Cooper pairing across the T=0 phase diagram of the two-dimensional Hubbard Model, relevant for high-temperature superconductors, using a cluster extension of dynamical mean field theory. We find that the…
We consider the one-band Hubbard model on the square lattice by using variational and Green's function Monte Carlo methods, where the variational states contain Jastrow and backflow correlations on top of an uncorrelated wave function that…
The Roth's two-pole approximation has been used by the present authors to investigate the role of $d-p$ hybridization in the superconducting properties of an extended $d-p$ Hubbard model. Superconductivity with singlet $d_{x^2-y^2}$-wave…
It is expected that at weak to intermediate coupling, d-wave superconductivity can be induced by antiferromagnetic fluctuations. However, one needs to clarify the role of Fermi surface topology, density of states, pseudogap, and wave vector…
We improve a previous theory of doped Mott insulators with duality between pairing and magnetism by a further duality transform. As the result we obtained a quantum Ginzburg-Landau theory describing the Cooper pair condensate and the dual…
Using the variational cluster approach based on the self-energy functional theory, we study the possible occurrence of excitonic order and superconductivity in the two-orbital Hubbard model with intra- and inter-orbital Coulomb…
Tools of quantum information theory offer a new perspective to characterize phases and phase transitions in interacting many-body quantum systems. The Hubbard model is the archetypal model of such systems and can explain rich phenomena of…
We explore the ground-state properties of the two-band Hubbard model with degenerate electronic bands, parametrized by nearest-neighbor hopping $t$, intra- and inter-orbital on-site Coulomb repulsions $U$ and $U^\prime$, and Hund coupling…
I present a microscopic theory I proposed recently to describe high-T_c superconductivity in cuprates. I show that coherent pairing states consisting of extended singlet Cooper pairs and triplet $\pi$ pairs can manifest both the Mott…
The high-temperature superconductivity in copper oxides emerges when carriers are doped into the parent Mott insulator. This well-established fact has, however, eluded a microscopic explanation. Here we show that the missing link is the…
Many theoretical approaches find d-wave superconductivity in the prototypical one-band Hubbard model for high-temperature superconductors. At strong-coupling (U > W, where U is the on-site repulsion and W=8t the bandwidth) pairing is…
We theoretically study the superconducting properties of multi-band two-dimensional transition metal oxide superconductors by analyzing not only the role played by conventional singlet pairings, but also by the triplet order parameters,…
The kinetic features of holes (electrons) in the Hubbard model are studied using a variational Monte Carlo method. In doped Mott insulators (U>U_co), holes are classified, in the sense of conduction, into two categories: (i) The holes…
The high-temperature superconducting cuprates host unidirectional spin- and charge-density-wave orders that can intertwine with superconductivity in non-trivial ways. While the charge components of these stripes have now been observed in…
In this thesis, we theoretically examine the pairing mechanisms and the identification of the pairing symmetry of unconventional superconductors whose normal states are correlated, multiband, or topological. In the first part, we…
Superfluid stiffness $\rho_s$ is a defining characteristic of the superconducting state, allowing phase coherence and supercurrent. It is accessible experimentally through the penetration depth. Coexistence of $d$-wave superconductivity…
The single band, two dimensional Hubbard Hamiltonian has been extensively studied as a model for high temperature superconductivity. While Quantum Monte Carlo simulations within the dynamic cluster approximation are now providing…
Motivated by the recent resurgence of interest in topological superconductivity, we study in this paper superconducting pairing instabilities of the hole-doped Rashba-Hubbard model on the square lattice with first- and second-neighbor…
Physics of high-$T_c$ superconducting cuprates is obscured by the effect of strong electronic correlations. One way to overcome the problem is to seek for an exact solution at least within the small cluster and expand it to the whole…
In the ionic Hubbard model, the onsite repulsion $U$, which drives a Mott insulator and the ionic potential $V$, which drives a band insulator, compete with each other to open up a window of charge fluctuations when $U \sim V$. We study…