相关论文: Spin fluctuations and the "strange metal" behavior…
Although spin fluctuations are central to the physics of high-Tc cuprates, their relevance to strange-metal behavior in the overdoped regime remains unclear. Here, we use high magnetic fields to suppress superconductivity and an NMR…
A model of CuO$_2$ planes of cuprate perovskites, containing $d_{x^2-y^2}$ copper orbitals and symmetric combinations of oxygen $p_\sigma$ orbitals, is investigated using the strong coupling diagram technique. This approach allows one to…
Overdoped cuprate superconductors are strange metals above their superconducting transition temperature. In such materials, the electrical resistivity has a strong linear dependence on temperature ($T$) and electrical current is not carried…
The superconducting properties of a recently proposed phenomenological model for a weakly doped antiferromagnet are analyzed, taking into account fluctuations of the phase of the order parameter. In this model, we assume that the doped…
On the basis of the Hubbard model, we present the formulation of antiferromagnetism in electron-doped cuprates using the fluctuation-exchange approach. Taking into account the spin fluctuations in combination with the impurity scattering…
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…
The magnon energy and amplitude renormalization due to intraband particle-hole excitations are studied in a metallic antiferromagnet. The change in sign of the intraband contribution with $\omega$ results in significant differences between…
It is a distinct possibility that spin fluctuations are the pairing interactions in a wide range of unconventional superconductors. In the case of the high-transition-temperature (high-$T_c$) cuprates, in which superconductivity emerges…
It is shown that the charge susceptibility in nearly half-filled two-dimensional (2D) metals, with technically nested Fermi surface, shows anomaly at the wavevector different from that for the spin susceptibility at low temperatures. Namely…
Spin fluctuations represent the lowest established energy scale in cuprates and are crucial for the understanding of anomalous normal state properties and superconductivity in these materials. The memory-function approach to the spin…
Local magnetic properties around a nonmagnetic impurity are investigated in high-Tc cuprate superconductors. We consider a model two-dimensional d-wave superconductor with strong antiferromagnetic (AF) spin fluctuations and calculate the…
We investigate the presence of antiferromagnetic fluctuations in the longitudinal and transversal spin susceptibilities of a square lattice. The inclusion of both first and second neighbour hopping terms, along with exchange coupling,…
Correlation effects in CuO$_2$ layers give rise to a complicated landscape of collective excitations in high-T$_{\rm c}$ cuprates. Their description requires an accurate account for electronic fluctuations at a very broad energy range and…
We analyze the two-dimensional {\it d-p} model, considering both antiferromagnetic spin fluctuation and $d_{x^2-y^2}$-wave superconducting fluctuation. We adopt the fluctuation-exchange approximation in order to derive both normal and…
The spectral function of transverse spin fluctuations, including the contributions from both the single-particle and the collective (magnon) excitations in an antiferromagnet, is evaluated for the Hubbard model with NN and NNN hoppings in…
Theories of the origin of superconductivity in cuprates are dependent on an understanding of their normal state which exhibits various competing orders. Transport and thermodynamic measurements on La$_{2-x}$Sr$_x$CuO$_4$ show signatures of…
We study the spin excitations and the transverse susceptibility of a two-dimensional antiferromagnet doped with a small concentration of holes in the t-J model. The motion of holes generates a renormalization of the magnetic properties. The…
Neutron scattering shows that non-Fermi-liquid behavior of the heavy-fermion compound CeNi_2Ge_2 is brought about by the development of low-energy spin fluctuations with an energy scale of 0.6 meV. They appear around the antiferromagnetic…
We study the properties of generalized striped phases of doped cuprate planar quantum antiferromagnets. We invoke an effective, spatially anisotropic, non-linear sigma model in two space dimensions. Our theoretical predictions are in…
Using numerical techniques we study the spectral function $A(k,\omega)$ of a spin-fermion model for cuprates in the regime where magnetic and charge domains (stripes) are developed upon hole-doping. From $A(k,\omega)$ we study the…