Related papers: Goldstone-mode effects and scaling function for th…
We present results from our analysis of the finite-temperature properties of the spin 1/2 $J_{1}$-$J_{2}$ Heisenberg model on a square lattice. The analysis is based on the exact diagonalization of small clusters with 16 and 20 sites…
Low-temperature magnetic properties of the one-dimensional Kondo-lattice model with classical localized spins are investigated by means of a Monte Carlo simulation combined with an exact diagonalization technique. Comparative simulations…
We investigate the low temperature magnetic phases in TmB_4, a metallic quantum magnet on the geometrically frustrated Shastry-Sutherland lattice, using co-ordinated experimental and theoretical studies. Our results provide an explanation…
A full energy spectrum, magnetization and susceptibility of a spin-1/2 Heisenberg model on two edge-shared tetrahedra are exactly calculated by assuming two different coupling constants. It is shown that a ground state in zero field is…
The four dimensional Gaussian random field Ising magnet is investigated numerically at zero temperature, using samples up to size $64^4$, to test scaling theories and to investigate the nature of domain walls and the thermodynamic limit. As…
The magnetization field and temperature dependences in the paramagnetic phase of Mn1-xFexSi solid solutions with x<0.3 are investigated in the range B<5 T and T<60 K. It is found that field dependences of the magnetization M(B,T=const)…
We study the finite-size scaling of moments of the magnetization in the low-temperature phase of the two-dimensional Ising model.
We analyze scaling functions in the $3$-$d$, $Z(2)$, $O(2)$ and $O(4)$ universality classes and their finite size dependence using Monte Carlo simulations of improved $\phi^4$ models. Results for the scaling functions are fitted to the…
Magnetoelectric properties of a coupled spin-electron model on a doubly decorated square lattice in an external electric field applied along the crystallographic axis [11] are rigorously examined with the help of generalized…
Monte Carlo simulations of a model for $\gamma$-Fe$_2$O$_3$ (maghemite) single particle of spherical shape are presented aiming at the elucidation the specific role played by the finite size and the surface on the anomalous magnetic…
We report measurements on in-plane resistivity, thermopower, and magnetization as a function of temperature and magnetic fields on single crystalline Sr4Ru3O10 grown by the floating zone method. As the temperature was lowered to below…
The large, so-called colossal, magnetoresistivity of doped manganese oxides based on LaMnO3 has attracted considerable attention, but only one unusual feature of the ferromagnetic transition in these compounds. We examine in this paper the…
The Goldstone mode due to stripe or unidirectional charge-density-wave order in electron systems is found to have the same functional form as the one in classical smectic liquid crystals. It is very similar to the Goldstone mode that…
We investigate numerically the finite-size scaling properties of the domain wall energies in the three-dimensional gauge glass model. From the analysis of results obtained for systems of linear sizes $3\le L\le 8$ we conclude that the…
Motivated by a recent experiment on volborthite, a typical spin-$1/2$ antiferromagnet with a kagom\'{e} lattice structure, we study the magnetization process of a classical Heisenberg model on a spatially distorted kagom\'{e} lattice using…
We report magnetization measurements on La(2-x)Sr(x)NiO(4+ delta) single crystals, with 0 < x < 0.5. Glassy behaviour associated with the formation of spin-charge stripes, and a separate spin-glass phase at low temperatures were observed.…
We argue that in an inflationary cosmology a consequence of the lack of time translational invariance is that spontaneous breaking of a continuous symmetry and Goldstone's theorem \emph{do not} imply the existence of \emph{massless}…
We report on structural, magnetic, electrical, and thermodynamic properties of Gd-doped LaMnO3 single crystals for Gd doping levels 0 <= x <= 1. At room temperature, for all doping levels the orthorhombic O' phase is indicative for a strong…
Magnetization processes of Ising models with frustration on diamond hierarchical lattices, which contain vertices with high coordination numbers, are exactly obtained at zero temperature. In antiferromagnetic systems, the magnetization…
Formation of magnetically ordered state in the Kondo lattices is treated within the degenerate $s-f$ exchange and Coqblin-Schrieffer models. The Kondo renormalizations of the effective coupling parameter, magnetic moment and spin excitation…