Related papers: Phenomenological theory of nonergodic phenomena in…
A simple description of thermodynamics of DMAAS and DMAGaS ferroelectric crystals by means of Landau expansion is proposed. Conditions of occurrence of phase transitions are established and their temperatures are obtained. The influence of…
Phenomenological thermodynamic theory describing the properties of metastable states in disordered ferromagnets and ferroelectrics with frustrative random interactions is developed and its ability to describe various nonergodic phenomena in…
We predict the existence of abnormal volcano-like temperature dependence of polarization or magnetization with maxima located at elevated temperature, distinct from classical model based on Landau theory. One case is ferroelectricity with…
It was recently observed that materials showing most striking multiferroic phenomena are frustrated spin-density-wave magnets. We present a simple phenomenological theory, which describes the orientation of the induced electric polarization…
Statistical theory of the dielectric susceptibility of polar liquid crystals is proposed. The molecules are not uniaxial but similar to cones. It is assumed that the permanent dipole moment of a molecule is parallel to the axis of the…
A mean-field model of Ising spin glass with the Hamiltonian being a sum of the infinite-range ferromagnetic and random antiferromagnetic interactions is studied. It is shown that this model has phase transition in external magnetic field…
Symmetry analysis provides crucial insights into the magnetoelectric coupling effect in type-II multiferroics. In this Letter, we comprehensively investigate couplings between electric polarization and inhomogeneous magnetization across all…
Statistical theory of the dielectric susceptibility of polar liquid crystals is proposed. The molecules are calamitic or bent-core but the permanent dipole moment is perpendicular to the molecule long axis. The ordering of the phase is…
We show that development of polar order may spontaneously destroy the lamellar structure of a liquid crystal. This results in an unusual sequence of phases with the ferroelectric nematic phase appearing below a non-polar smectic phase. The…
The correlations of the free-energy landscape of mean-field spin glasses at different temperatures are investigated, concentrating on models with a first order freezing transition. Using a ``potential function'' we follow the metastable…
We propose Landau phenomenology for describing the phase transition from the conventional nematic into the conical helical orientationally non-uniform structure recently identified in liquid crystals formed by "banana"-shaped molecules. The…
We present a theory to study the temperature-dependent behavior of surface states in a ferromagnetic semi-infinite crystal. Our approach is based on the single-site approximation for the \emph{s-f} model. The effect of the semi-infinite…
Low temperature properties of glasses are derived within a generalized tunneling model, considering the motion of charged particles on a closed path in a double-well potential. The presence of a magnetic induction field B violates the time…
Using Landau theory, it is shown that eight phenomenological parameters are needed to describe and distinguish the twelve viscosity coefficients of a biaxial nematic phase, or the five viscosity coefficients of a uniaxial nematic phase. The…
Motivated by the rapidly growing possibilities for experiments with ultracold atoms in optical lattices we investigate the thermodynamic properties of correlated lattice fermions in the presence of an external spin-dependent random…
The thermodynamics of an electrically charged, multicomponent fluid with spontaneous electric dipoles and magnetic moments is analysed in the presence of electromagnetic fields. Taking into account the chemical composition of the current…
We discuss magnetization curves of a toy-model trigonal and tetrahedral clusters. Nonlinearity of magnetization with local minimum of differential susceptibility resembling known magnetization plateaus of triangular-lattice and pyrochlore…
Puzzling observations of both thermal and dielectric responses in multi-silicate glasses at low temperatures $T$ to static magnetic fields $B$ have been reported in the last decade and call for an extension of the standard two-level systems…
While particle-based ices are often considered essentially equivalent to magnet-based spin ices, the two differ essentially in frustration and energetics. We show that at equilibrium particle-based ices correspond exactly to spin ices…
A generalized tunneling model of insulating glasses is formulated, considering tunneling states to be paramagnetic centers of spin 1/2. The expression for magnetic field dependent contribution into the free energy is obtained. The…