Related papers: High-Field Low-Frequency Spin Dynamics
Although spin cycloids and helices are quite common, remarkably little is known about the normal modes of a spin cycloid or helix with finite length on a discrete lattice. Based on simple one-dimensional lattice models, we numerically…
In certain mild extensions of the Standard Model, spin-independent long range forces can arise by exchange of two very light pseudoscalar spin--0 bosons. In particular, we have in mind models in which these bosons do not have direct tree…
Current-driven spin torques in metallic spin-valves composed of antiferromagnets are theoretically studied using the non-equilibrium Green's function method implemented on a tight-binding model. We focus our attention on G-type and L-type…
Spin dynamics in spatially inhomogeneous magnetic fields is studied within the framework of Boltzmann theory. Stern-Gerlach-like separation of spin up and spin down electrons occurs in ballistic and diffusive regimes, before spin relaxation…
In many transition metal compounds, in particular those containing Fe^{2+} and Co^{3+}, there occur spin-state transitions between low-spin and high-spin (or intermediate-spin) states. We show that typical interactions between similar…
The multiple-spin exchange frequencies of the bilayer Wigner crystal are determined by the semiclassical method, which is asymptotically exact in the limit of dilute electron densities. The evolution of the exchange frequencies with…
We consider bosons in a Hubbard lattice with an SU($\cal N$) pseudospin degree of freedom which is made dynamical via a coherent transfer term. It is shown that, in the basis which diagonalizes the pseudospin coupling, a generic hopping…
The stable magnetisation configurations of antiferromagnets on quasiperiodic tilings are investigated theoretically. The exchange coupling is assumed to decrease exponentially with the distance between magnetic moments. It is demonstrated…
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…
Superexchange calculation is performed for multi-orbital band models with broken inversion symmetry. Orbital-changing hopping terms allowed by the symmetry breaking electric field lead to a new kind of orbital exchange term closely…
We figure out that the ground state of a multiple-spin exchange model applicable to thin films of solid 3He possesses an octahedral spin nematic order. In the presence of magnetic field, it is deformed into an antiferro-quadrupolar order in…
Experimentally an asymmetry of the reversal modes has been found in certain exchange bias systems. From a numerical investigation of the domain state model evidence is gained that this effect depends on the angle between the easy axis of…
The Goldstone theorem mandates that a spontaneous symmetry breaking entails the emergence of gap(mass)less excitations. In the case where a rotational invariance of a system of spin magnetic moments is broken by an antiferromagnetic order,…
The extended dynamical mean field theory has played an important role in the study of quantum phase transitions in heavy fermion systems. In order to incorporate the physics of unconventional superconductivity, we develop a cluster version…
A field theory approach for the nonequilibrium relaxation dynamics in open systems at late times is developed. In the absence of conservation laws, all excitations are subject to dissipation. Nevertheless, ordered stationary states satisfy…
This work examines the magnetic order and spin dynamics of a double-exchange model with competing ferromagnetic and antiferromagnetic Heisenberg interactions between the local moments. The Heisenberg interactions are periodically arranged…
The spin dynamics at the finite temperature for the t-J model in the underdoped and optimal doped regimes is studied within the fermion-spin theory. It is shown that the dynamical spin structure factor spectrum at the antiferromagnetic wave…
We present the phenomenological analysis of the spectrum of longitudinal spin fluctuations in isotropic itinerant electron antiferromagnets with account of spin anharmonicity giving rise to coupling of transverse and longitudinal normal…
An argument is made on the existence of a low-temperature itinerant antiferromagnetic (AF) spin alignment, rather than persistent helical (PH), in the ground state of a two dimensional electron gas in a semiconductor quantum well with…
We present a study, within a mean-field approach, of the kinetics of a mixed ferrimagnetic model on a square lattice in which two interpenetrating square sublattices have spins that can take two values, $\sigma=\pm1/2$, alternated with…