Related papers: Real-space d-wave superconductivity from weak attr…
We demonstrate that the infinite-$U$ triangular-lattice Hubbard model supports a superconducting state built from tightly bound Cooper pairs composed of two holes and one magnon ($2h1m$). Building on the seminal prediction of repulsively…
A microscopic theory of the electronic spectrum and of superconductivity within the t-J model on the honeycomb lattice is developed. We derive the equations for the normal and anomalous Green functions in terms of the Hubbard operators by…
We explore how the superconductivity arising from the on-site electron-electron repulsion will change when the repulsion is changed to a long-ranged, 1/r-like one by introducing an extended Hubbard model with the repulsion extending to…
YBa$_2$Cu$_3$O$_7$ (YBCO) exhibits a large anisotropy between the $a$ and $b$ axes in the CuO$_2$ planes because of the presence of CuO chains. In order to account for such an anisotropy we develop a Ginzburg-Landau (GL) theory for an…
Unconventional strongly correlated phases of the repulsive Fermi-Hubbard model, which could be emulated by ultracold vapors loaded in optical lattices, are investigated by means of energy minimizations with quantum number projection before…
We derive a pair potential from tight binding further neighbours attraction that leads to superconducting gap symmetry similar to that of the phenomenological spin fluctuation theory of high temperature superconductors (Monthoux, Balatsky,…
We discuss a few possibilities of high-$T_c$ superconductivity with more than one orbital symmetry contributing to the pairing. First, we show that the high energies of orbital excitations in various cuprates suggest a simplified model with…
We use the microscopic weak coupling theory to predict the pairing state in superconductors of cubic, hexagonal, or tetragonal symmetry, where the order parameter is multicomponent, i.e., transforms according to either a 2-dimensional or a…
The vortex lattice structures of Sr$_2$RuO$_4$ for the odd parity representations of the superconducting state are examined for the magnetic field along the crystallographic directions. Particular emphasis is placed upon the two dimensional…
A microscopic calculation and symmetry argument reveal superconductivity in the vicinity of parity-violating magnetic order. An augmented cluster magnetic multipole order in a crystal lacking local space inversion parity may break global…
The mechanism of superconductivity in cuprates remains one of the big challenges of condensed matter physics.High Tc cuprates crystallize into layered perovskite structure featuring copper oxygen octahedral coordination. Due to the Jahn…
Using a dynamic cluster quantum Monte Carlo approximation, we study a two-dimensional Hubbard model with a small orthorhombic distortion in the nearest neighbor hopping integrals. We find a large nematic response in the low-frequency…
Within the spin-fermion model for cuprate superconductors, the influence of the intersite Coulomb interactions $V_2$ and $V_2'$ between holes located at the next-nearest-neighbor oxygen ions of CuO$_2$ plane on the implementation of the…
We examine superconductivity in LaAlO$_3$/SrTiO$_3$ channels in which the channel width transitions from the 1D to 2D regime. The superconducting critical current is independent of the channel width and increases approximately linearly with…
Superlattices of the repeated structure La(1.56)Sr(0.44)CuO(4)/La(2)CuO(4) (LSCO-LCO), where none of the constituents is superconducting, show a superconducting transition of T_c \simeq 25 K. In order to elucidate the nature of the…
It is shown that the properties of the superconductivity observed in Sr$_2$RuO$_4$ can be accounted for by properly taking into account the internal degrees of freedom of the system. The electrons are strongly correlated in the RuO$_2$…
We study the superconducting transition in the attractive Hubbard model in two dimensions using the self-consistent $T$-matrix approximation. We demonstrate that for large system sizes, this approximate method produces XY critical scaling…
The pairing mechanism in cuprates remains as one of the most challenging issues in the field of condensed matter physics. The unique 3d9 electron orbital of the Cu2+ ionic states in cuprates is supposed to be the major player for the…
The oxygen O2p_sigma and copper Cu4s and Cu3d_x^2-y^2 orbitals are involved in a simple LCAO model for determination of the conduction band and the oxygen-oxygen hopping is considered as a small parameter with respect to the transition…
The superconducting phase of the high-Tc cuprates has been thought to be described by a single d-wave pairing order parameter. Recently, there has been growing evidence suggesting that another form of order, possibly inherited from the…