Related papers: High temperature superconductivity in the two-dime…
A theory of strongly correlated electron or hole liquids with the fermion condensate is presented and applied to the consideration of quasiparticle excitations in high temperature superconductors, in their superconducting and normal states.…
We investigate the properties of cuprate superconductors subject to applied current, using modified Gutzwiller projected d-wave BCS states. The parent states include quasiparticle and quasihole pockets, of variationally determined size,…
Spatially inhomogeneous electronic states are expected to be key ingredients for the emergence of superconducting phases in quantum materials hosting charge-density-waves (CDWs). Prototypical materials are transition-metal dichalcogenides…
The attractive Fermi-Hubbard model is the simplest theoretical model for studying pairing and superconductivity of fermions on a lattice. Although its s-wave pairing symmetry excludes it as a microscopic model for high-temperature…
We study properties of normal, superconducting (SC) and CDW states for an attractive Hubbard model on the square lattice, using a variational Monte Carlo method. In trial wave functions, we introduce an interspinon binding factor,…
We study the electronic structure of a strongly correlated d-wave superconducting state. Combining a renormalized mean field theory with direct calculation of matrix elements, we obtain explicit analytical results for the nodal Fermi…
We analyze superconducting state (both s and d - wave) in a simple exactly solvable model of pseudogap state, induced by short - range order fluctuations (e.g. antiferromagnetic), which is based upon model Fermi - surface with "hot…
A model of a strongly correlated electron liquid based on the fermion condensation (FC) is extended to high-temperature superconductors. Within our model, the appearance of FC presents a boundary separating the region of a strongly…
The high energy spin excitation in the high T$_{c}$ cuprates is studied in the single mode approximation for the $t-t'-J$ model. An exact form for the mode dispersion is derived. When the Gutzwiller projected BCS state is used as the…
The superconducting gap structure of a charge density wave (CDW) superconductor LaPt$_2$Si$_2$ ($T_c$ = 1.6~K) having a quasi two dimensional crystal structure has been investigated using muon spin rotation/relaxation ($\mu$SR) measurements…
The stability and other properties of a staggered flux (SF) state or a correlated d-density wave state are studied for the Hubbard (t-t'-U) model on extended square lattices, as a low-lying state that competes with the d(x2-y2)-wave…
With high-Tc cuprates in mind, properties of correlated dx2-y2-wave superconducting (SC) and antiferromagnetic (AF) states are studied for the Hubbard (t-t'-U) model on square lattices, using a variational Monte Carlo method. We employ…
We analyze solutions to a superconducting gap equation based on the two-dimensional Hubbard model with nearest and next-to-nearest neighbor hopping. The Cooper pair potential can be calculated exactly and expressed in terms of elliptic…
We present analytic results for ground-state properties of Hubbard-type models in terms of the Gutzwiller variational wave function with non-zero values of the magnetization m. In dimension D=1 approximation-free evaluations are made…
The possibility of superconductivity (SC) in the 2D Hubbard model (2DH) was investigated by means of the variational Monte Carlo method. The energy gain of the d-wave SC state, obtained as the difference of the minimum energy with a finite…
Mechanisms of Mott transitions and dx2-y2-wave superconductivity (SC) are studied in the half-filled-band Hubbard model on square lattices with a diagonal hopping term (t'), using an optimization (or correlated) variational Monte Carlo…
Motivated by the presence of an extremely small electron pocket in the electronic band structure of infinite-layer (IL) nickelate superconductors, we systematically explore the superconducting (SC) properties of a two-dimensional Hubbard…
We have introduced a Coulomb correlated normal state to study the superconducting pairing with a Fermi liquid like normal phase background in a 3 dimensional system. The role of the Coulomb correlation has been actively incorporated by…
The two-dimensional Hubbard model is studied for small values of the interaction strength (U of the order of the hopping amplitude t), using a variational ansatz well suited for this regime. The wave function, a refined Gutzwiller ansatz,…
We study the quantum corrections to the Fermi energy of a two-dimensional electron system, showing that it is attracted towards the Van Hove singularity for a certain range of doping levels. The scaling of the Fermi level allows to cure the…