Related papers: Solitons and (spin-)Peierls transition in disorder…
We study the effects of weak off-diagonal disorder on Peierls systems with a doubly degenerate ground state. We show that for these systems disorder in the electron hopping amplitudes induces a finite density of solitons in the…
We study the competition between the spin-Peierls and the antiferromagnetic ordering in disordered quasi-one-dimensional spin systems. We obtain the temperature vs disorder-strength phase diagram, which qualitatively agrees with recent…
We present a theory for the spin-Peierls transition in CuGeO_3. We map the elementary excitations of the dimerized chain (solitons) on an effective Ising model. Inter-chain coupling (or phonons) then introduce a linear binding potential…
The interplay of charge, spin and lattice degrees of freedom is studied for quasi-one-dimensional electron and spin systems coupled to quantum phonons. Special emphasis is put on the influence of the lattice dynamics on the Peierls…
We investigate thermodynamic properties of a one-dimensional S=1/2 antiferromagnetic Heisenberg model coupled to a lattice distortion by a quantum Monte Carlo method. In particular we study how spin and lattice dimerize as a function of the…
Effects of disorder and external field on the competing spin-Peierls and antiferromagnetic states are studied theoretically in terms of the numerical transfer matrix method applied to a quasi one-dimensional spin 1/2 Heisenberg model…
The chromium spinels MgCr2O4 and ZnCr2O4 are prime examples of the highly frustrated pyrochlore lattice antiferromagnet. Experiment has carefully established that both materials, upon cooling, distort to lower symmetry and order…
Temperature-dependent x-ray diffraction of the low-dimensional spin 1/2 quantum magnet TiOCl shows that the phase transition at T_{c2} = 90 K corresponds to a lowering of the lattice symmetry. Below T_{c1} = 66 K a twofold superstructure…
The spin-Peierls transition is modeled in the dimer phase of the spin-$1/2$ chain with exchanges $J_1$, $J_2 = \alpha J_1$ between first and second neighbors. The degenerate ground state generates an energy cusp that qualitatively changes…
One-dimensional non-equilibrium kinetic Ising models evolving under the competing effect of spin flips at zero temperature and nearest-neighbour spin exchanges exhibiting directed percolation-like parity conserving(PC) phase transition on…
We examine spin-Peierls systems in the presence of spin defects which are introduced by replacing magnetic ions $Cu^{2+}$ with non-magnetic ones $Zn^{2+}$ in $CuGeO_3$. By using the action for the bosonized Hamiltonian, it is shown directly…
The zero and finite temperature spin-Peierls transitions in a quasi-one-dimensional spin-1/2 Heisenberg model coupled to adiabatic bond phonons is investigated using the Stochastic Series Expansion (SSE) Quantum Monte Carlo (QMC) method.…
The microscopic description of the spin-Peierls transition in pure and doped CuGeO_3 is developed taking into account realistic details of crystal structure. It it shown that the presence of side-groups (here Ge) strongly influences…
A model of disordered spin-Peierls system is considered, where domain walls are randomly distributed as a telegraph noise. For this realization of the disorder in an XX spin chain, we calculate exactly the density of states as well as…
Phase transitions of the mixed spin-1/2 and spin-S (S >= 1/2) Ising model on a three-dimensional (3D) decorated lattice with a layered magnetic structure are investigated within the framework of a precise mapping relationship to the simple…
Using the numerical approach for a study of the thermodynamic properties of the nonuniform one-dimensional spin-1/2 isotropic XY model in a transverse field we examine different lattice distortions to reveal which spin-Peierls phases are…
We study the triangular lattice Ising model with a finite number of vertically stacked layers and demonstrate a low temperature reentrance of two Berezinskii-Kosterlitz-Thouless transitions, which results in an extended disordered regime…
A theoretical approach to the influence of one-dimensional lattice fluctuations on electronic properties in weakly localized spin-Peierls systems is proposed using the renormalization group and the functional integral techniques. The…
The sequence of phase transitions and the symmetry of in particular the low temperature incommensurate and spin-Peierls phases of the quasi one-dimensional inorganic spin-Peierls system TiOX (TiOBr and TiOCl) have been studied using…
Most common types of symmetry breaking in quasi-one-dimensional electronic systems possess a combined manifold of states degenerate with respect to both the phase $\theta$ and the amplitude $A$ sign of the order parameter $A\exp(i\theta)$.…