相关论文: Ordered phases in spin-Peierls systems
The interest in the study of spin-Peierls phenomenon has increased with the discovery of copper germanium oxide (CuGeO_3) as an example of spin-Peierls systems. The availability of this inorganic compound as large, high quality single…
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…
An overview is given of Raman and infrared spectroscopic studies of the inorganic spin-Peierls compound CuGeO$_3$, with an emphasis on the magnetic fluctuations in the uniform, dimerized, and high field phases of this quasi one dimensional…
The phase diagram of a model describing doped CuGeO$_3$ is derived. The model emphasizes the role of local moments released by the impurities and randomly distributed inside the gaped singlet background. The phase diagram is investigated by…
Phases and phase transitions in pure and doped spin-Peierls system CuGeO_3 are considered on the basis of a Landau-theory. In particular we discuss the critical behaviour, the soliton width and the low temperature specific heat of the…
A magnetic model is proposed for describing the incommensurate I phase of spin-Peierls systems. Based on the harmonicity of the lattice distortion, its main ingredient is that the distortion of the lattice adjusts to the average…
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…
Two-dimensional colloidal suspensions exposed to periodic external fields exhibit a variety of molecular crystalline phases. There two or more colloids assemble at lattice sites of potential minima to build new structural entities, referred…
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…
In view of recent developments in the investigation on cuprate high-T${}_{\rm c}$ superconductors and the spin-Peierls compound CuGeO${}_{3}$, we study the effect of dilute impurity doping on the spin-Peierls state in quasi-one dimensional…
The data on the dispersion of the magnetic excitations of CuGeO_3 in the spin-Peierls dimerized phase are analyzed. On the basis of the lattice structure it is shown that even along the chains the $d=2$ character cannot be neglected. The…
I consider a theoretical description of recent experiments on doping the spin-Peierls compound CuGeO$_3$ and the Haldane gap compounds PbNi$_2$V$_2$O$_8$ and Y$_2$BaNiO$_5$. The effective theory is the one of randomly distributed spin-$1/2$…
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…
In many materials, ordered phases and their order parameters are easily characterized by standard experimental methods. "Hidden order" refers to a phase transition in which an ordered state emerges without such an easily detectable order…
The impurity induced antiferromagnetic ordering of the doped spin-Peierls magnet Cu(1-x)Mg(x)GeO(3) was studied by ESR technique. Crystals with the Mg concentration x<4% demonstrate a coexistence of paramagnetic and antiferromagnetic ESR…
Partially phase-separated liquid-crystal/polymer dispersions display highly fibrillar domain morphologies that are dramatically different from the typical structures found in isotropic mixtures. To explain this, we numerically explore the…
Ferroics, characterized by a broken symmetry state with nonzero elastic, polar, or magnetic order parameters $\vec{u}$, are recognized platforms for staging and manipulating topologically-protected structures as well as for detecting…
Large spin systems can exhibit unconventional types of magnetic ordering different from the ferromagnetic or N\'eel-like antiferromagnetic order commonly found in spin 1/2 systems. Spin-nematic phases, for instance, do not break…
A spin system is studied, with simultaneous permutation-symmetric Potts and spin-rotation-symmetric clock interactions, in spatial dimensions d=2 and 3. The global phase diagram is calculated from the renormalizaton-group solution with the…