Related papers: Spin waves in La_2CuO_4: band structure and correl…
The exact 2-spinon part of the dynamic spin structure factor $S_{xx}(Q,\omega)$ for the one-dimensional $s$=1/2 $XXZ$ model at $T$=0 in the antiferromagnetically ordered phase is calculated using recent advances by Jimbo and Miwa in the…
The on-site Coulomb potential, U, and the covalent state of electronic orbitals play key roles for the Cooper pair symmetry and exotic electromagnetic properties of high-Tc superconducting cuprates. In this paper, we demonstrate a way to…
We study the ground state quantum spin fluctuations around the N\'eel ordered state for the one-band ($t,U$) Hubbard model on a site-diluted square lattice. An effective spin Hamiltonian, $H_{\rm s}^{(4)}$, is generated using the canonical…
We present inelastic neutron scattering measurements of the antiferromagnetic insulator CaMn$_2$Sb$_2$, which consists of corrugated honeycomb layers of Mn. The dispersion of magnetic excitations has been measured along the H and L…
We elucidate the role of magnon interaction and spontaneous decays in the spin dynamics of the triangular-lattice Heisenberg antiferromagnet by calculating its dynamical structure factor within the spin-wave theory. Explicit theoretical…
We have studied the static and dynamic magnetic properties of two-dimensional (2D) and quasi-two-dimensional, spin-S, quantum Heisenberg antiferromagnets (QHAF) diluted with spinless vacancies. Using spin-wave theory and T-matrix…
Excitation spectra of square lattice Heisenberg antiferromagnets in magnetic fields are investigated by the spin-wave theory. It is pointed out that a rotonlike structure appears in a narrow range of magnetic fields, as a result of strong…
Recent neutron scattering measurements reveal spin and charge ordering in the half-doped nickelate, La$_{3/2}$ Sr$_{1/2}$ NiO$_4$. Many of the features of the magnetic excitations have been explained in terms of the spin waves of diagonal…
We apply a random-plaquette $J_1$-$J_2$ model on the square lattice to capture the physics of a series of spin-$1/2$ Heisenberg antiferromagnet compounds Sr$_2$CuTe$_{1-x}$W$_x$O$_6$. With the input of experimentally relevant coupling…
The spin gap of a one-dimensional repulsive Hubbard model is numerically calculated with the density matrix renormalization group, with a special emphasis on the effect of a next-nearest neighbor hopping (t') and the nearest-neighbor…
We study the mean-field phase diagram of the two-dimensional (2D) Hubbard model in the Lieb lattice allowing for spin and charge density waves. Previous studies of this diagram have shown that the mean-field magnetization surprisingly…
Using an atomistic spin model, we have simulated spin wave injection and propagation into antiferromagnetic IrMn from an exchange coupled CoFe layer. The spectral characteristics of the exited spin waves have a complex beating behavior…
The effect of antiferromagnetic interchain coupling in alternating spin (1,1/2) chains is studied by mean of spin wave theory and density matrix renormalization group(DMRG). Two limiting cases are investigated, the two-leg ladder and its…
We present a quantum kinetic theory for spin-$1/2$ particles, including the spin-orbit interaction, retaining particle dispersive effects to all orders in $\hbar$, based on a gauge-invariant Wigner transformation. Compared to previous…
We investigate the magnetic properties of the Cu-O planes in stoichiometric Sr$_{n-1}$Cu$_{n+1}$O$_{2n}$ (n=3,5,7,...) which consist of CuO double chains periodically intergrown within the CuO$_2$ planes. The double chains break up the…
Recent inelastic neutron scattering (INS) experiments on La$_{2-x}$Sr$_x$CuO$_4$ observed a {\it magnetic coherence effect}, i.e., strong frequency and momentum dependent changes of the spin susceptibility, $\chi''$, in the superconducting…
We study the antiferromagnetic phase of the Kondo lattice model on bipartite lattices at half-filling using the dynamical mean-field theory with numerical renormalization group as the impurity solver, focusing on the detailed structure of…
We investigate the Hubbard model on a two-dimensional square lattice by the perturbation expansion to the fourth order in the on-site Coulomb repulsion U. Numerically calculating all diagrams up to the fourth order in self-energy, we…
The first study of two-dimensional electron gas in surface layers on HgMnTe with inverted bands is carried out experimentally and theoretically. It is shown that the structure of investigated capacitance magnetooscillations in HgMnTe MOS…
Inelastic neutron scattering is used to investigate magnetic excitations in the quasi-one-dimensional quantum spin-liquid system Cu2Cl4 D8C4SO2. Contrary to previously conjectured models that relied on bond-alternating nearest neighbor…