Related papers: Spin dynamics in lightly doped La$_{2-x}$Sr$_x$CuO…
At zero temperature magnetic phases of the quantum spin-1/2 Heisenberg antiferromagnet on a simple cubic lattice with competing first and second neighbor exchanges (J1 and J2) is investigated using the non-linear spin wave theory. We find…
We report polarized- and unpolarized- neutron inelastic scattering measurements of the magnetic excitation spectrum in the spin-charge ordered phase of La3/2Sr1/2NiO4. Up to energies of ~30 meV we observe broad magnetic modes characteristic…
We report a comparative study of 63Cu Nuclear Magnetic Resonance spin lattice relaxation rates, T_1^{-1}, on undoped SrCuO_2 and Ca doped Sr_{0.9}Ca_{0.1}CuO_2 spin chain compounds. A temperature independent T_1^{-1} is observed for SrCuO_2…
The low-energy properties of the two-dimensional Heisenberg model with spin-$\frac{1}{2}$ on a square lattice are investigated on the basis of the local dimer order. The lattice is divided into square blocks consisting of the quartet of…
We consider nuclear spin-lattice relaxation rate resulted from a fractional diffusion equation for anomalous rotational wobbling in a cone. The mechanism of relaxation is assumed to be due to dipole-dipole interaction of nuclear spins and…
We unravel theoretically a key intrinsic relaxation mechanism among the low-lying singlet and triplet donor-pair states in silicon, an important element in the fast-developing field of spintronics and quantum computation. Despite the…
We study spin fluctuations in the spiral phase of the two-dimensional Hubbard model at low doping on the basis of the spin-particle-hole coherent-state path integral. In the strong correlation limit, we obtain an analytical expression 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…
We study how doping destroys the AF order in the layered cuprates within the framework of the charge--transfer insulator concept. We use the criterion of stability of the AF background to show that the stability problem is one of the main…
The hole concentration dependence of the magnetic correlations is studied in very lightly-doped La$_{2-x}$Sr$_x$CuO$_4$ ($x<$0.02), which shows coexistence of a three-dimensional antiferromagnetic (AF) long-range ordered phase and a…
Temperature-dependent dynamical spin correlations, which can be readily accessed via a variety of experimental techniques, hold the potential of offering a unique fingerprint of quantum spin liquids and other intriguing dynamical states. In…
We report a systematic study by 75As nuclear-quadrupole resonance in LaFeAsO1-xFx. The antiferromagnetic spin fluctuation (AFSF) found above the magnetic ordering temperature TN = 58 K for x = 0.03 persists in the regime 0.04 < x < 0.08…
We study the low temperature dynamics of the classical Heisenberg antiferromagnet with nearest neighbour interactions on the pyrochlore lattice. We present extensive results for the wavevector and frequency dependence of the dynamical…
We study dynamics and relaxation of elementary excitations (magnons) in the spin nematic (quadrupole ordered) phase of S=1 magnets. We develop a general phenomenological theory of spin dynamics and relaxation for spin-1 systems. Results of…
Within the t-J model, the optical and transport properties of the doped two-leg ladder antiferromagnet are studied based on the fermion-spin theory. It is shown that the optical and transport properties of the doped two-leg ladder…
Cluster perturbation theory is applied to the two-dimensional Hubbard $t-t'-t''-U$ model to obtain doping and temperature dependent electronic spectral function with $4 \times 4$ and 12-site clusters. It is shown that evolution of the…
Nuclear spin-lattice relaxation in one-dimensional Heisenberg ferrimagnets is studied by means of a modified spin-wave theory. We consider the second-order process, where a nuclear spin flip induces virtual spin waves which are then…
Muon spin relaxation ($\mu$SR) measurements in high transverse magnetic fields ($\parallel \hat c$) revealed strong field-induced quasi-static magnetism in the underdoped and Eu doped (La,Sr)$_{2}$CuO$_{4}$ and…
We probe the spin dynamics in a thin magnetic film at ferromagnetic resonance by nuclear resonant scattering of synchrotron radiation at the 14.4 keV resonance of $^{57}$Fe. The precession of the magnetization leads to an apparent reduction…
The spin dynamics of the semiclassical Heisenberg model with uniaxial anisotropy, on the layered triangular lattice with antiferromagnetic coupling for both intralayer nearest neighbor interaction and interlayer interaction is studied both…