Related papers: Spin-Phonon Chains with Bond Coupling
We investigate the anti-adiabatic limit of an anti-ferromagnetic S=1/2 Heisenberg chain coupled to Einstein phonons. The flow equation method is used to decouple the spin and the phonon part of the Hamiltonian. In the effective spin model…
We performed a finite-temperature quantum Monte Carlo simulation of the one-dimensional spin-1/2 Heisenberg model with nearest-neighbor interaction coupled to Einstein phonons. Our method allows to treat easily up to 100 phonons per site…
By applying a quantum Monte Carlo procedure based on the loop algorithm we investigate thermodynamic properties of the two-dimensional antiferromagnetic S=1/2 Heisenberg model coupled to Einstein phonons on the bonds. The temperature…
We develop an analytical approach based on a unitary transformation to investigate S=1/2 antiferromagnetic Heisenberg chains coupled to phonons, and find a new quantum phase transition at zero temperature. Although the usual phase…
The spin-Peierls instability in spin 1/2 XY chain coupled to dispersionless phonons of frequency $\omega$ has been studied in the nonadiabatic limit. We have chosen the Lang-Firsov variational wave function for the phonon subsystem to…
Using a new version of the density-matrix renormalization group we determine the phase diagram of a model of an antiferromagnetic Heisenberg spin chain where the spins interact with quantum phonons. A quantum phase transition from a gapless…
A model with Holstein-like electron-phonon coupling is studied in the limit of adiabatic phonons. The phonon distribution is anharmonic with two degenerate maxima. This model can be related to fermions in a correlated binary alloy and…
A high order series expansion is employed to study the thermodynamical properties of a S=1/2 chain coupled to dispersionless phonons. The results are obtained without truncating the phonon subspace since the series expansion is performed…
A spin and phonon excitations spectrum are studied using quantum Monte Carlo method in antiferromagnetic chain with spins $S=1/2$ coupled nonadiabaticity with acoustic phonons . It is found the critical coupling exists to open gap in the…
We present results for the spin conductance of the one dimensional spin-1/2 Heisenberg and XY model coupled to phonons. We apply an approach based on the Stochastic Series Expansion (Quantum Monte Carlo) method to evaluate the conductance…
As a simple model for spin-Peierls systems we study a frustrated Heisenberg chain coupled to optical phonons. In view of the anorganic spin-Peierls compound CuGeO3 we consider two different mechanisms of spin-phonon coupling. Combining…
We study the effect of bond dissipation on the one-dimensional antiferromagnetic spin-$1/2$ Heisenberg model. In analogy to the spin-Peierls problem, the dissipative bath is described by local harmonic oscillators that modulate the spin…
We investigate a one-dimensional S=1 antiferromagnetic Heisenberg model coupled to a lattice distortion by a quantum Monte Carlo method. Investigating the ground state energy of the static bond-alternating chain, we find that the…
We study an extended model to describe the spin-lattice coupling, incorporating individual vibrations of bonds and atomic sites alongside distance-dependent exchange interactions. The proposed spin Hamiltonian can be effectively considered…
We investigate a model of a frustrated spin-1/2 Heisenberg chain coupled to adiabatic phonons with a general form of magnetoelastic coupling. For large enough frustration and lattice coupling a new tetramerised phase with three different…
Asymptotic properties of nearly-half-filled one-dimensional conductors coupled with phonons are studied through a renormalization group method. Due to spin-charge coupling via electron-phonon interaction, the spin correlation varies with…
We investigate elastic deformations of spin $S=1/2$ antiferromagnetic $J_1-J_2$ Heisenberg chains, at $M=1/3$ magnetization, coupled to phonons in the adiabatic approximation. Using a bosonization approach we predict the existence of…
We explore the ground-state phase diagram of a Heisenberg spin chain coupled locally to optical phonons (bond coupling), using large-scale density matrix renormalization group calculations and an extended perturbative analysis. For the…
We consider a model of Raman scattering for a two--dimensional $S=1/2$ Heisenberg Anti-Ferromagnet which includes a {\it dynamical} spin--phonon interaction. We observe a broadening of the line shape due to increased coupling with excited…
The interplay of bond and charge correlations is studied in a one-dimensional model with both Holstein and Su-Schrieffer-Heeger (SSH) couplings to quantum phonons. The problem is solved exactly by quantum Monte Carlo simulations. If one of…