Related papers: Local Antiferromagnetic Correlations and $d_{x^2-y…
In cuprate superconductors, due to strong electronic correlations, there are multiple intertwined orders which either coexist or compete with superconductivity. Among them the antiferromagnetic (AF) order is the most prominent one. In the…
We study the superconducting pairing correlations in the ground state of the doped Hubbard model -- in its original form without hopping beyond nearest neighbor or other perturbing parameters -- in two dimensions at intermediate to strong…
We generalize the theory of Cooper pairing by spin excitations in the metallic antiferromagnetic state to include situations with electron and/or hole pockets. We show that Cooper pairing arises from transverse spin waves and from gapped…
A model for high-temperature superconductors incorporating antiferromagnetism, d-wave superconductivity, and no double lattice-site occupancy can give energy surfaces exquisitely balanced between antiferromagnetic and superconducting order…
I show that for a \kappa-type organic (BEDT-TTF)_2-X molecular crystal, a superconducting state with T_c ~ 10 K and gap nodes on the Fermi surface can be caused by short-ranged antiferromagnetic spin fluctuations. Using a two-band…
Exact diagonalizations of two dimensional small t--J clusters reveal dominant hole-hole correlations at distance $\sqrt{2}$ (ie between holes on next nearest neighbor sites). A new form of singlet $d_{x^2-y^2}$ pair operator is proposed to…
Strong electron correlations lie at the origin of transformative phenomena such as colossal magneto-resistance and high-temperature superconductivity. Already near room temperature, doped copper oxide materials display remarkable features…
We study the anomalous normal state properties of a simple two-dimensional model whose ground state is a d-wave superconductor. Using a self-consistent, conserving formulation, we show that pairing correlations above T_c lead to the…
The antiferromagnetic correlation plays an important role in high-T$_{c}$ superconductors. Considering this effect, the magnetic excitations in n-type cuprates near the optimal doping are studied within the spin density wave description.…
The two-leg Hubbard ladder is characterized by the ratio of the inter- to intra-leg hopping t_perp/t, the relative interaction strength U/t and the electron filling. Here, using density matrix renormalization group and Monte Carlo…
We explore multiband effects on d-wave superconducting instabilities driven by electron-electron interactions. Our models on the two-dimensional square lattice consist of a main band with an extended Fermi surface and predominant weight…
The enigma of unconventional superconductivity in doped cuprates presents a formidable challenge in the realm of condensed matter physics. Recent findings of strong near-neighbor attractions in one-dimensional cuprate chains suggest a new…
We review the recent developments in the field of cuprate superconductors with the special focus on the recently observed charge order in the underdoped compounds. We introduce new theoretical developments following the study of the…
We extend the methods recently introduced in Phys. Rev. Lett. 106 036401 (2011) to investigate correlations between two spin-polarons in a quasi-two-dimensional CuO2 layer. The low-energy wavefunctions for two doped holes introduced in a…
Motivated by the recent experiment in multilayered cuprate superconductors reporting the enhancement of antiferromagnetic order below the superconducting transition temperature, we study the proximity effect of the antiferromagnetic…
The d-wave pairing correlations along with spin correlation are calculated with quantum Monte Carlo method for the two-dimensional Hubbard model on lattice structures representing organic superconductors $\kappa$-(BEDT-TTF)$_2$X and…
We deduce a model relevant for the description of the ferromagnetic half-metal Chromium dioxide ($CrO_{2}$), widely used in magnetic recording technology. The model describes the effect of dynamical, local orbital correlations arising from…
We study the phase diagram of the Hubbard model in the weak-coupling limit for coexisting spin-density-wave order and spin-fluctuation-mediated superconductivity. Both longitudinal and transverse spin fluctuations contribute significantly…
The electromagnetic response of the CuO2-planes is calculated within a strong coupling theory using model tight binding bands and momentum dependent pairing interactions representing spin fluctuations and phonon exchange. The…
Much remains unknown of the microscopic origin of superconductivity when it materializes in atomically disordered systems as in amorphous alloys (1) or in crystals riddled with defects(2). A manifestation of this conundrum is envisaged in…