Related papers: Spin and Charge Fluctuations in the $\alpha$-struc…

We study two types of models for the superconducting layered nitride $\beta$-MNCl(M=Hf,Zr); a single band model on a triangular lattice, and a two band model on a honeycomb lattice. We find that the former model does not suffice as an…

In their article, Zhang et al. [Phys. Rev. B 86, 024516 (2012)] present a remarkable result for A$_x$(S)$_y$TiNCl compounds ($\alpha$-phase TiNCl partially intercalated with alkali A and optionally co-intercalated molecular species S),…

This paper describes the first 63-Cu NMR study of an electron-doped infinitely-layered high Tc superconductor Sr$_0.9$La$_0.1$CuO$_2$ (Tc=42K). The spin dynamics in the normal state above Tc exhibits qualitatively the same behavior as some…

We investigate the magnetic and superconducting properties in electron-doped Li$_x$HfNCl. HfNCl is a band insulator that undergoes an insulator to superconductor transition upon doping at $x\approx0.13$. The persistence of the insulating…

A recent analysis of optical conductivity data which has provided strong evidence for coupling of the charge carriers to the 41 meV spin resonance, seen in the superconducting state of optimally doped Y123, is extended to other systems. We…

We present an ab initio analysis with density functional theory for superconductors (SCDFT) to understand the superconducting mechanism of doped layered nitrides \beta-Li$_x$MNCl (M=Ti, Zr, and Hf). The current version of SCDFT is based on…

Spin fluctuation-induced superconductivity in quasi-two dimensional organic compounds, \kappa-BEDT-TTF salts, is investigated within a fluctuation exchange (FLEX) approximation using a half-filled Hubbard model with a right-angled isosceles…

We introduce and study a realistic model for superconductivity in twisted bilayer WSe$_{2}$, where electron pairing arises from spin-valley fluctuations in the weak-coupling regime. Our model comprises both the full continuum model…

Understanding the complexities of electronic and magnetic ground states in solids is one of the main goals of solid-state physics. Materials with the canonical ThCr$_2$Si$_2$-type structure have proved particularly fruitful in this regards,…

The in-plane infrared response of the high-Tc cuprate superconductors was studied using the spin-fermion model, where charged quasiparticles of the copper-oxygen planes are coupled to spin fluctuations. First, we analyzed structures of the…

We propose that if there are two small pocket-like Fermi surfaces, and the spin susceptibility is pronounced around a wave vector {\bf Q} that bridges the two pockets, the spin-singlet superconductivity mediated by spin fluctuations may…

We have theoretically investigated the spin and charge fluctuations in the quasi-one dimensional organic superconductor (TMTSF)2ClO4. Using the extended multi-site Hubbard model, which contains four sites in a unit cell and the transfer…

Superconductivity was recently observed in boron-doped ($\sqrt{3}\times\sqrt{3}$)Sn/Si(111). The material can be described by an extended Hubbard model on a triangular lattice. Here, we use the random-phase approximation to investigate the…

The discovery of superconductivity at 80 K under high pressure in La$_3$Ni$_2$O$_7$ presents the groundbreaking confirmation that high-$T_c$ superconductivity is a property of strongly correlated materials beyond cuprates. We use density…

The recent discovery of ambient-pressure superconductivity in thin-film bilayer nickelates opens new possibilities for investigating electronic structures in this new class of high-transition temperature $T_C$ superconductors. Here, we…

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…

The recently reported nickel carbide superconductor, body centered tetragonal $I4/mmm$ Th$_2$NiC$_2$ with T$_c$ = 8.5 K increasing to 11.2 K upon alloying Th with Sc, is found to have very fine structure in its electronic spectrum,…

Neutron scattering has been used to study the spin fluctuations in the YBa$_2$Cu$_3$O$_{7-x}$ and Bi$_2$Sr$_2$CaCu$_2$O$_8$ materials. Evidence is found for both incommensurate fluctuations and a commensurate resonance excitation.…

The quantum spin fluctuations of the S = 1/2 Cu ions are important in determining the physical properties of the high-transition temperature (high-Tc) copper oxide superconductors, but their possible role in the electron pairing for…

We report $^{125}$Te nuclear magnetic resonance and $^{181}$Ta nuclear quadrupole resonance studies on single-crystal Ta$_{4}$Pd$_{3}$Te$_{16}$, which has a quasi-one-dimensional structure and superconducts below $T_{\rm c}=4.3$ K.…