Related papers: Dynamic Spin Correlation Function of the Alternati…
It is demonstrated that there is anti-ferromagnetic spin-spin interaction between nearest electrons in the 2D Wigner crystal. This is also valid for the Wigner liquid - the state with destroyed long-range order but preserved short-range…
We analyze the phases of an S=1/2 spin model on a lattice of coupled tetrahedra. The presence of both Heisenberg and antisymmetric, Dzyaloshinsky-Moriya interactions can lead to two types of symmetry-broken states: non-magnetic dimer order…
Spin-fluctuation-mediated superconductivity is conventionally associated with d_{x^2-y^2} pairing. We show that a generalized model of antiferromagnetic spin fluctuations in three dimensions may also yield a state with formal ``s-wave''…
Synthetic spin-orbit coupling in cold atoms couples the pseudo-spin and spatial degrees of freedom, and therefore the inherent spin symmetry of the system plays an important role. In systems of two pseudo-spin degrees, two particles contain…
We discuss the transition strength between the disordered ground state and the basic low-lying triplet excitation for interacting dimer materials by presenting theoretical calculations and series expansions as well as inelastic neutron…
Motivated by recent work on Heisenberg antiferromagnetic spin systems on various lattices made up of triangles, we examine the low-energy properties of a chain of antiferromagnetically coupled triangles of half-odd-integer spins. We derive…
Two-leg spin-1/2 ladder systems consisting of a ferromagnetic leg and an antiferromagnetic leg are considered where the spins on the legs interact through antiferromagnetic rung couplings $J_1$. These ladders can have two geometrical…
We study a one-dimensional electron liquid coupled by a weak spin-exchange interaction to an antiferromagnetic spin-S ladder with n legs. A perturbative renormalization group analysis in the semiclassical limit reveals the opening of a spin…
A relaxation-function theory for the dynamic spin susceptibility in the $t$--$J$ model is presented. By a sum-rule-conserving generalized mean-field approximation (GMFA), the two-spin correlation functions of arbitrary range, the staggered…
We use the density matrix renormalization group method to study the ground state `phase' diagram and some low-energy properties of isotropic antiferromagnetic spin-$1 \over 2$ and spin-$1$ chains with a next-nearest neighbor exchange $J_2…
The dynamical dimer structure factor is an observable probing spin-singlet excitations of quantum magnets distinct from those commonly studied by the spin structure factor. We report the dimer response for the extended spin-$1/2$…
A linear spin wave analysis of dimerization of alternating Heisenberg system with spins $s_{1}$ and $s_{2}$ on linear chain as well as square lattice is presented. Among the several possible dimerized configurations considered in two…
Ordering of frustrated S=1/2 and 1 XY and Heisenberg spin chains with the competing nearest- and next-nearest-neighbor antiferromagnetic couplings is studied by exact diagonalization and density-matrix renormalization-group methods. It is…
Properties of low-dimensional spin-Peierls systems are described by using a one dimensional S=1/2 antiferromagnetic Heisenberg chain linearly coupled to a single phonon mode of wave vector pi (whose contribution is expected to be dominant).…
We investigate a spin-1/2 antiferromagnetic chain with trimerized exchange couplings relevant to Na$_2$Cu$_3$Ge$_4$O$_{12}$. We show that the low-energy Hilbert space maps onto an effective Heisenberg chain of composite spin-1/2 trimer…
We present accurate numerical estimates for the correlation amplitudes of leading and main subleading terms of the two- and four-spin correlation functions in the one-dimensional spin-1/2 XXZ model under a magnetic field. These data are…
We report results from a systematic strong-coupling expansion of a spin-1/2 Heisenberg chain coupled to Einstein phonons. In the non-adiabatic regime this model is used to describe zero temperature properties of CuGeO3. The linked cluster…
We study a one-dimensional Hamiltonian consisting of coupled SU(2) spin and orbital degrees of freedom. Using the density matrix renormalization group, we calculate the phase-diagram and the ground state correlation functions for this…
We investigate spin correlations in one-dimensional $SU(2)$-invariant Heisenberg chains with exchange disorder for spin lengths $S=1/2$ and $S=1$. In the weak-disorder regime, the eigenmodes of the spin-spin correlation matrix are…
The spin dynamics of the geometrically frustrated triangular antiferromagnet multiferroic CuCrO2 have been mapped out using inelastic neutron scattering. The relevant spin Hamiltonian parameters modelling the incommensurate modulated…