Related papers: Spin Dynamics for the t-J Model
Many low dimensional spin systems with a dimerized or ladder-like antiferromagnetic exchange coupling have a gapped excitation spectrum with magnetic bound states within the spin gap. For spin ladders with an even number of legs the…
Using high temperature expansions for the equal time correlator $S(q)$ and static susceptibility $\chi(q)$ for the t-J model, we present evidence for quantum critical (QC), $z\!=\!1$, behavior at intermediate temperatures in a broad range…
Within the t-J model, the charge transport and spin response of the doped bilayer triangular antiferromagnet are studied by considering the bilayer interaction. Although the bilayer interaction leads to the band splitting in the electronic…
In the present paper, we study a system of doped antiferromagnet in three dimensions at finite temperatures by using the t-J model, a canonical model of strongly-correlated electrons. We employ the slave-fermion representation of electrons…
The spin-diffusion constant of the 2D $t-J$ model is calculated for the first time using an analytical approach at high temperatures and a recently-developed numerical method based on the Lanczos technique combined with random sampling in…
The supersymmetric formulation of t-J model is studied in this paper at the mean-field level where $\delta$-T phase diagram is computed. We find that slave-fermion-like spiral phase is stable at low doping concentration, and the…
Finite-temperature properties of weakly doped antiferromagnets as modeled by the two-dimensional t-J model and relevant to underdoped cuprates are investigated by numerical studies of small model systems at low doping. Two numerical methods…
The charge dynamics of the copper oxide materials in the underdoped and optimal doped regimes is studied within the framework of the fermion-spin theory. The conductivity spectrum shows the non-Drude behavior at low energies and unusual…
Starting from the Hubbard model in the weak-coupling limit, we derive a spin-fermion model where the collective spin excitations are described by a non-linear sigma model. This result is used to compute the fermion spectral function $A({\bf…
The self-consistent treatment of real and imaginary renormalizations in the dynamic spin susceptibility for the frustrated Heisenberg model reproduces for cuprates at low doping: a spin spectrum, a saddle point for q near (pi/2,pi/2),…
The spin structure in a magnetic dot, which is an example of a quantum few-body system, is studied as a function of exchange coupling strength and dot size with in the semiclassical approximation on a discrete lattice. As the exchange…
The electron spin resonance (ESR) spectroscopy was employed to investigate the spin dynamics in triangular lattice antiferromagnets CuCr$_{1-x}$Mg$_{x}$O$_2$ with $x =$ 0 and 0.02. All spectra can be well fitted by a single Lorentzian…
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…
All eigenstates and eigenvalues are determined for the spin- 1/2 $XXZ$ chain $H = 2J \sum_i ( S_{i}^{x} S_{i + 1}^{x} + S_{i}^{y} S_{i + 1}^{y} + \Delta S_i^z S_{i + 1}^{z})$ for rings with up to N=16 spins, for anisotropies $\Delta=0 ,…
We construct thermodynamics of the one-dimensional supersymmetric {\it t-J} model with the $ 1/\sin^2$ interaction and hopping. The thermodynamics is described exactly in terms of free spinons and holons obeying Haldane's fractional…
Low-frequency spin dynamics in the S=1/2 antiferromagnetic spin-chain compound \alpha-VO(PO_3)_2 has been studied by means of 31P NMR. The nuclear spin-lattice relaxation rate 1/T_1 at the P site exhibits H^{-1/2} dependence on the applied…
We revisit the dynamic spin susceptibility, $\chi(q,\omega)$, of one-dimensional interacting fermions. To second order in the interaction, backscattering results in a logarithmic correction to $\chi(q,\omega)$ at $q\ll k_F$, even if the…
The incommensurate spin fluctuation of the doped triangular antiferromagnet is studied within the t-J model. It is shown that the commensurate peak near the half-filling is split into six incommensurate peaks in the underdoped and optimally…
Inelastic neutron scattering measurements have been performed on single crystals of the heavy fermion compound Ce$_{0.925}$La$_{0.075}$Ru$_{2}$Si$_{2}$ in broad energy [0.1, 9.5 meV] and temperature [40 mK, 294 K] ranges in order to address…
The theory for the dynamical spin susceptibility within the t-J model is developed, as relevant for the resonant magnetic peak and normal-state magnetic response in superconducting (SC) cuprates. The analysis is based on the equations of…