相关论文: Order-Disorder Tricriticality in $\mathrm{A}_n \ma…

We review the theory of second--order (ferro--)elastic phase transitions, where the order parameter consists of a certain linear combination of strain tensor components, and the accompanying soft mode is an acoustic phonon. In…

The Kibble-Zurek (KZ) mechanism has been extensively studied in various second-order phase transitions, yet the case of tricriticality-the point where second-order phase transition lines terminate-remains experimentally elusive. Here, we…

Jahn--Teller (JT) distortions are a key driver of physical properties in many correlated oxide materials. Cooperative JT distortions, in which long-range orbital order reduces the symmetry of the average structure macroscopically, are…

X-ray scattering and polarized microscopic studies of the structure and order parameters in the nematic (N) and heliconical, or the twist-bend nematic (Ntb), phase have been performed as a function of temperature. The nematic orientational…

The origin of the non commutativity of the limits $t \to \infty$ and $N \to \infty$ in the dynamics of first order transitions is investigated. In the large-N model, i.e. $N \to \infty$ taken first, the low temperature phase is…

Glasses are ubiquitous in daily life and technology. However the microscopic mechanisms generating this state of matter remain subject to debate: Glasses are considered either as merely hyper-viscous liquids or as resulting from a genuine…

Dipolar spin ensembles with random spin positions attract much attention currently because they help to understand decoherence as it occurs in solid state quantum bits in contact with spin baths. Also, these ensembles are systems which may…

We investigate theoretically charge ordered states on the anisotropic triangular lattice characteristic of the theta-(BEDT-TTF)_2 X materials. Using exact diagonalization studies, we establish that the charge order (CO) pattern corresponds…

It is shown that the time-reversal symmetry is broken during the phase transition causing orbital ordering in a crystal with Jahn-Teller (J-T) ions. This means that such phase transitions are magnetic ones. As an example we have considered…

We show that rotation of the magnetic field off the plane of twin boundaries (TB's) induces transition of an ordered vortex solid phase to a disordered one. This transition arises due to appearance of transverse deformations of vortex lines…

Measurements of the electrical and thermal conductivities, thermopower and paramagnetic susceptibility have been performed on single crystal samples of Bi1/2Sr1/2MnO3 and complemented with the X-ray powder diffraction data. A pronounced…

We study the ground-state properties of a system of dimers. Each dimer consists in a pair of equivalent charges at a fixed distance, immersed in a neutralizing homogeneous background. All charges interact pairwisely by Coulomb potential.…

In this paper a spin-1 spin-glass model under the presence of a uniform crystal field is investigated. It is shown that the model presents both continuous and first-order phase transition separated by a tricritical point. The phase diagram…

The transition between the two phases of 4D Euclidean Dynamical Triangulation [1] was long believed to be of second order until in 1996 first order behavior was found for sufficiently large systems [5,9]. However, one may wonder if this…

We show that the exactly solved low-temperature branch of the two-dimensional O($n$) model is equivalent with an O($n$) model with vacancies and a different value of $n$. We present analytic results for several universal parameters of the…

How atoms in covalent solids rearrange over a medium-range length-scale during amorphization is a long pursued question whose answer could profoundly shape our understanding on amorphous (a-) networks. Based on ab-intio calculations and…

We have performed a Monte Carlo study of a classical three dimensional Coulomb system in which we systematically increase the positional disorder. We start from a completely ordered system and gradually transition to a Coulomb glass. The…

The critical behavior of a model colloid-polymer mixture, the so-called AO model, is studied using computer simulations and finite size scaling techniques. Investigated are the interfacial tension, the order parameter, the susceptibility…

The physical consequences of the spin-triplet, even-parity pairing that has been predicted to exist in disordered two-dimensional electron systems are considered in detail. We show that the presence of an attractive interaction in the…

Polymers with both soluble and insoluble blocks typically self-assemble into micelles, aggregates of a finite number of polymers where the soluble blocks shield the insoluble ones from contact with the solvent. Upon increasing…