相关论文: $d$-wave and $s^\pm$ Pairing Strengths in Ba$_2$Cu…

For the recently discovered cuprate superconductor $\mathrm{Ba_{2}CuO_{3+\delta}}$, we propose a lattice structure which resembles the model considered by Lieb to represent the vastly oxygen-deficient material. We first investigate the…

An intact CuO$_2$ plane is widely believed to be a prerequisite for the high-$T_c$ superconductivity in cuprate superconductors. However, an exception may exist in the superconducting Ba$_2$CuO$_{3+\delta}$ materials where CuO chains play a…

We investigate the superconducting pairing symmetry in pressurized La$_3$Ni$_2$O$_7$ based on a bilayer two-orbital model. There are two symmetric bands $\alpha$ and $\gamma$, as well as two antisymmetric ones $\beta$ and $\delta$. It is…

Using an RPA approximation, we have calculated the strengths of the singlet and triplet pairing interactions which arise from the exchange of spin and orbital fluctuations for a 2-orbital model of the Fe-pnictide superconductors. When the…

We demonstrate that a $d_{x^2-y^2}$ superconducting pairing is naturally associated with the screened Coulomb interaction $V_{eff}({\bf q},\omega)$ within the $CuO_2$ plane of high $T_c$ superconductors. This pairing instability arises (via…

The recently discovered cuprate superconductor Ba$_2$CuO$_{3+\delta}$ exhibits a high $T_c\simeq73$K at $\delta\simeq0.2$. The polycrystal grown under high pressure has a structure similar to La$_2$CuO$_4$, but with dramatically different…

Recent experiments in multiband Fe-based and heavy-fermion superconductors have challenged the long-held dichotomy between simple $s$- and $d$-wave spin-singlet pairing states. Here, we advance several time-reversal-invariant irreducible…

Here we calculate the strength of the $d$-wave pairing and the $k$ dependence of the gap function associated with the nematic fluctuations of a CuO$_2$ model as the doping $p$ approaches a quantum critical point. Higher order $d$-wave…

The $d$-wave pairing symmetry has long been considered a defining feature of high-temperature superconductivity in cuprates. In this work, we reveal that $s$-wave pairing states exhibit variational energies comparable to the $d$-wave state…

We study superconductivity in the two-dimensional 16-band d-p model extracted from a tight-binding fit to the band structure of LaFeAsO, using the random phase approximation. When the intraorbital repulsion U is larger than the interorbital…

In the Eliashberg integral equations for d-wave superconductivity, two different functions $(\alpha^2 F)_n(\omega, \theta)$ and $(\alpha^2 F)_{p,d}(\omega)$ determine, respectively, the "normal" and the "pairing" self-energies. We present a…

Although correlated electronic-structure calculations explain very well the normal state of Sr$_2$RuO$_4$, its superconducting symmetry is still unknown. Here we construct the spin and charge fluctuation pairing interactions based on its…

First principles investigations of the high temperature superconducting system Ba$_2$CuO$_{3+\delta}$, recently discovered at $\delta\approx0.2$ at $T_c=70$ K, are applied to demonstrate the effects of oxygen ordering on the electronic and…

Pair density wave superconductivity constitutes a novel electronic condensate proposed to be realized in certain unconventional superconductors. Establishing its potential existence is important for our fundamental understanding of…

The pairing symmetry is examined in highly electron-doped Ba(Fe$_{1-x}$Co$_x$As)$_2$ and A$_y$Fe$_2$Se$_2$ (with A=K, Cs) compounds, with similar crystallographic and electronic band structures. Starting from a phenomenological two-orbital…

In this study, we perform a numerical simulation on the recently discovered high-temperature superconductor ($T_c$= 73K) Ba$_2$CuO$_{3.2}$ \cite{lietal} while focusing on doping dependence of alternating CuO$_6$ octahedra and CuO chain-like…

The frequency structure of the superconducting correlations in cuprates gives insights on the pairing mechanism. Here we present an exhaustive study of this problem in the two-dimensional Hubbard model with cellular dynamical mean-field…

Pair density waves, identified by Cooper pairs with finite center-of-mass momentum, have recently been observed in copper oxide based high T$_\textrm{c}$ superconductors (cuprates). A charge density modulation or wave is also ubiquitously…

A mechanism of d_{x^2-y^2}-wave superconductivity is proposed for the high-T_c cuprates based on a spin texture with non-zero topological density induced by doped holes through Zhang-Rice singlet formation. The pairing interaction arises…

The nature of the pairing state in iron-based superconductors is the subject of much debate. Here we argue that in one material, the stoichiometric iron pnictide KFe2As2, there is overwhelming evidence for a d-wave pairing state,…