相关论文: Anti-ferromagnetism, spin-phonon interaction and t…

Effects of coupling between phonon distortions and stripe-like spin waves in the CuO plane of HgBa$_2$CuO$_4$ are studied by band calculations. Local exchange enhancements depend sensitively on the local structure around Cu sites.…

A comprehensive study of doped RVB states is performed. It reveals a fundamental connection between superconductivity and quantum spin fluctuations in underdoped cuprates : {\em Cooper pair hopping} strongly reduces the local magnetization…

The mechanism of spin-phonon coupling in high-T$_C$ copper oxides is explored from band calculations on La$_{(2-x)}$Sr$_x$CuO$_4$ and HgBa$_2$CuO$_4$ systems. The LMTO band calculations, based on the local density approximation, are made…

We investigate the electronic structure of (Sr$_{1-x}$La$_x$)$_2$RhO$_4$ using a combination of the density functional and dynamical mean-field theories. Unlike the earlier local density approximation plus Hubbard $U$ (LDA+U) studies, we…

Band calculations show that a stripe-like anti-ferromagnetic spin wave is enforced by a 'half-breathing' phonon distortion within the CuO plane of HgBa_2CuO_4. This spin-phonon coupling is increased further by shear distortion and by…

Band calculations for the hole doped La$_2$CuO$_4$ system show that artificial periodicities of Ba dopants can give the material different properties than from a uniform distribution of dopants. A periodicity within the planes make static…

First principle band calculations based on local versions of density functional theory (DFT), together with results from nearly free-electron models, can describe many typical but unusual properties of the high-$T_C$ copper oxides. The…

A combination of density functional theory in its local density approximation (LDA) with k- and $\omega $ dependent self-energy found from fluctuational-exchange-type random phase approximation (FLEX-RPA) is utilized here to study…

We determine where a given concentration of ferromagnetic (FM) bonds doped into a square lattice antiferromagnet must go to minimize the system's total magnetic energy. We find (i) an infinite degeneracy of ground--state arrangements of FM…

In this article I give a pedagogical illustration of why the essential problem of high-Tc superconductivity in the cuprates is about how an antiferromagnetically ordered state can be turned into a short-range state by doping. I will start…

Spin-polarized band calculations for supercells of SrB$_{6}$, where a La-, In- or Al- impurity or a vacancy is replacing one Sr, are performed within the local spin density approximation. Moderately large cells with 8 formula units (56…

Recent results on electrons and holes doped CuO 2 planes confirm the marked covalency of CuO bonding, suggesting a band picture of long and short range antiferromagnetism. The maxima of superconductive T c versus doping can be related to…

Measurements of the specific heat on the system Ca$_{1-x}$La$_{x}$MnO$_{3}$ (% $x\leq 0.10$) are reported. Particular attention is paid to the effect that doping the parent compound with electrons by substitution of La for Ca has on the…

In this Letter we discuss various properties of the local density of states (DOS) for a superconductor-ferromagnet hybrid system. The DOS is modified at small energies on both sides of the interface. Due to the interplay of…

The band structures of pure and hole doped La$_2$CuO$_4$ with antiferromagnetic (AFM) spin-fluctuations are calculated and compared to spectral weights of ARPES. It is shown that observations of coexisting Fermi surface (FS) arcs and closed…

Iridates such as Sr$_2$IrO$_4$ are of considerable interest owing to the formation of the Mott insulating state driven by a large spin-orbit coupling. However, in contrast to the expectation from the Nagaoka Theorem that a single doped hole…

Using the Density Matrix Renormalization Group and two-leg ladders, we investigate an electronic two-orbital Hubbard model including plaquette diagonal hopping amplitudes. Our goal is to search for regimes where charges added to the undoped…

The possibility of superconductivity in doped and undoped triangular antiferromagnets is discussed. Using the Bethe-Salpeter (B-S) equation, it is shown that the exchange of RPA paramagnons on a triangular lattice Hubbard model leads to…

The properties of the phonon-induced interaction between electrons are studied using the local density approximation (LDA). Restricting the electron momenta to the Fermi surface we find generally that this interaction has a pronounced peak…

Using ultrafast optical techniques, we detect two types of bosons strongly coupled to electrons in the family of Bi$_{2}$Sr$_{2}$CaCu$_{2}$O$_{8+\delta}$ from the underdoped to overdoped regimes. The different doping dependences of the…