相关论文: Spin susceptibility in a pseudogap state with fluc…
Two-sublattice ferrimagnet, with spin-$s_1$ operators $\bf{S_{1i}}$ at the sublattice $A$ site and spin-$s_2$ operators $\bf{S_{2i}}$ at the sublattice $B$ site, is considered. The magnon of the system, the transversal fluctuation of the…
The pseudogap phenomena observed on cuprate high temperature superconductors are investigated based on the exact diagonalization method on the finite cluster t-J model. The results show the presence of the gap-like behavior in the…
We use the $1/M$ expansion for the $CP^{M-1}$ model to study the long-distance behaviour of the staggered spin susceptibility in the commensurate, two-dimensional quantum antiferromagnet at finite temperature. At $M=\infty$ this model…
We present a theory for inelastic neutron scattering (INS) and nuclear magnetic resonance (NMR) experiments in the pseudo-gap regime of the underdoped high-$T_c$ cuprates. We show that superconducting phase fluctuations greatly affect the…
We propose an explanation of several experimental features related to the ``pseudogap'' in HTS cuprates in terms of a spin-charge gauge theory approach to the t-J model. The metal-insulator crossover as temperature decreases is explained…
The leading superconducting instabilities of the two-dimensional extended repulsive one-band Hubbard model within spin-fluctuation pairing theory depend sensitively on electron density, band and interaction parameters. We map out the phase…
Quantum fluctuations of the N\'eel state of the square lattice antiferromagnet are usually described by a $\mathbb{CP}^1$ theory of bosonic spinons coupled to a U(1) gauge field, and with a global SU(2) spin rotation symmetry. Such a theory…
The letter deals with the spin-freezing process observed by means of NMR-NQR relaxation or by muon spin rotation in underdoped cuprate superconductors. This phenomenon, sometimes referred as coexistence of antiferromagnetic and…
We derive in detail a novel solution of the spin fermion model which is valid in the quasi-static limit pi T<<omega_sf, found in the intermediate (pseudoscaling) regime of the magnetic phase diagram of cuprate superconductors, and use it to…
The most intriguing observation of cuprate experiments is most likely the metal-insulator-crossover (MIC), seen in the underdome region of the temperature-doping phase diagram of copper-oxides under a strong magnetic field, when the…
We consider a two-layer Heisenberg antiferromagnet which can be either in the N\'{e}el-ordered or in the disordered phase at $T=0$, depending on the ratio of the intra- and interlayer exchange constants. We reduce the problem to an…
An improved U(1) slave-boson approach is applied to study the optical conductivity of the two dimensional systems of antiferromagnetically correlated electrons over a wide range of hole doping and temperature. Interplay between the spin and…
In strongly correlated materials, interacting electrons are entangled and form collective quantum states, resulting in rich low-temperature phase diagrams. Notable examples include cuprate superconductors, in which superconductivity emerges…
In this paper, we try to understand the pseudogap phenomenon observed in the cuprate superconductor through a model study. Specifically, we explore the so-called low-temperature pseudogap state by turning off the superconducting off…
Spin states of two-dimensional Wigner clusters are considered at low temperatures, when all electrons are in ground coordinate states. The spin subsystem behavior is determined by antiferromagnetic exchange integrals. The spin states in…
An investigation of possibilities for superconductivity mediated by spin fluctuations in some elementary metals is motivated by the recent discovery of superconductivity in the hcp high-pressure phase of iron. The electronic structure, the…
A magnetic susceptibility which decreases with decreasing temperature is observed in all $CuO_2$ based superconductors with less than optimal doping. We propose that in $La_{2-x} Sr_x CuO_4$ this is due to antiferromagnetic ordering which…
We summarize the present status of the theories of spin fluctuations in dealing with the anomalous or non-Fermi liquid behavior and unconventional superconductivity in strongly correlated electron systems around their magnetic instabilities…
The high-temperature superconducting cuprates are governed by intertwined striped magnetic and charge orders in addition to superconductivity. Remarkably similar behavior has also been seen in numerical calculations for the Hubbard model…
Disorder in materials may be used to tune their functionalities, but much more strikingly, its presence can entail entirely new behavior. This happens in charge-ice where structural disorder is not weak and local, but strong and long-range…