Related papers: Tilt order parameters, polarity and inversion phen…
Many molecular theories of nematic liquid crystals consider the constituent molecules as cylindrically symmetric. In many cases, this approximation may be useful. However the molecules of real nematics have lower symmetry. Therefore a…
Chiral liquid crystals exhibit in-plane spontaneous polarizations, however in their smectic phase the primary order parameter is a tilt vector associated with molecular rotations around the long molecular axis parallel to the director. The…
Thermoelastic phenomena associated with orientational phase transition in solid C60 are considered. Coupling of the order parameter with elastic strain is analyzed in the Landau theory of phase transitions. Wide range of possible…
Recently Wang et al. [Phys. Rev. Lett. 104, 027801 (2010)] discovered a new polar smectic phase with six-layer period (SmC*d6). In this manuscript, we demonstrate that the theory [Phys. Rev. E 67, 041716 (2003)] based on the free energy…
Recent liquid-crystalline (LC) research is focused on structurally new molecular systems distinct from simple nematic or smectic phases. Sophisticated molecular shape may reveal structural complexity, combining helicity and polarity.…
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…
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 report on X-ray studies of freely suspended hexatic films of three different liquid crystal compounds. By applying angular X-ray cross-correlation analysis (XCCA) to the measured diffraction patterns the parameters of the…
We study the smectic AC transition in anisotropic and uniaxial disordered environments, e.g., aerogel with an external field. We find very strange behavior of translational correlations: the low-temperature, lower-symmetry Smectic C phase…
We report the first observation of the smectic C--smectic I (C--I) critical point by Xray diffraction studies on a binary system. This is in confirmity with the theoretical idea of Nelson and Halperin that coupling to the molecular tilt…
Symmetry provides important insight in understanding the nature of phase transitions. In the presence of crystalline symmetries, new phenomena in phase transition can emerge, such as intertwined orders and emergent symmetries. In this work,…
The degree of randomness, or partial order, present in two-dimensional supramolecular arrays of isophthalate tetracarboxylic acids is shown to vary due to subtle chemical changes such as the choice of solvent or small differences in…
We propose a Landau-de Gennes phenomenological model to describe the pressure induced smectic A-nematic phase transition. The pressure induced smectic A phase transitions are discussed for varying coupling between orientational and…
When translational symmetry is broken by bulk disorder, the topological nature of states in topological crystalline systems may change depending on the type of disorder that is applied. In this work, we characterize the phases of a…
A theoretical study of toroidal membranes with various degrees of intrinsic orientational order is presented at mean-field level. The study uses a simple Ginzburg-Landau style free energy functional, which gives rise to a rich variety of…
We present a theory of the elasticity and fluctuations of the Smectic A and C phases in uniaxial, anisotropic disordered environments, e.g., stretched aerogel. We find that, bizarrely, the low-temperature, lower-symmetry Smectic $C$ phase…
We report Monte-Carlo simulation studies of some systems consisting of polar rod-like molecules interacting via a pair potential that exhibit liquid crystal phases, attributed with tilt angles of large magnitude. For theoretical…
Experimental and modeling/simulation studies of phase equilibrium and growth morphologies of novel polymer-dispersed liquid crystal (PDLC) mixtures of PS (polystyrene) and liquid crystals that exhibit a direct isotropic/smectic-A (lamellar)…
We revisit the chiral transition in the finite density Sakai-Sugimoto model and find that, at fixed temperature $T$, the magnetisation near the critical line $\mu_c(B)$ acts as an order parameter to distinguish Inverse Magnetic Catalysis…
The most important recent results in the theory of phase transitions and quantum effects in quantum anharmonic crystals are presented and discussed. In particular, necessary and sufficient conditions for a phase transition to occur at some…