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Related papers: Landau theory for helical nematic phases

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Extensions of a previously presented Landau-de Gennes type liquid crystalline phase transition model for the direct isotropic/smectic-A (lamellar) a phase transition to the direct isotropic/smectic-C (tilted lamellar) transition are…

Soft Condensed Matter · Physics 2008-12-02 Nasser Mohieddin Abukhdeir , Alejandro D. Rey

A version of the second order phase transition theory, in which the Nernst theorem holds automatically, is proposed. The theory is constructed in terms of the order parameter and the (configurational) entropy. It faithfully reproduces the…

Statistical Mechanics · Physics 2015-05-15 Metlov S. Leonid

The thermodynamic model of visco-elastic deformable magnetic materials at finite strains is formulated in a fully Eulerian way in rates. The Landau theory applies for ferro-to-para-magnetic phase transition, the gradient theory (leading…

Analysis of PDEs · Mathematics 2023-02-07 Tomáš Roubíček

Abstract Characterizing the crystalline disorder properties of the heterovalent ternary semiconductors continues to challenge solid-state theory. Here, a Landau theory is developed for the wurtzite-based ternary semiconductor ZnSnN2. It is…

Mesoscale and Nanoscale Physics · Physics 2019-08-06 Paul C. Quayle

The pressure-driven tetragonal-to-monoclinic phase transition in CaWO4 and related scheelite-structured orthotungstates is analysed in terms of spontaneous strains. Based upon our previous high-pressure x-ray diffraction results and the…

Materials Science · Physics 2007-05-23 D. Errandonea

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…

Soft Condensed Matter · Physics 2013-01-21 Shaikh M. Shamid , David W. Allender

In chiral ferromagnets, weak spin-orbit interactions twist the ferromagnetic order into spirals, leading to helical order. We investigate an extended Ginzburg-Landau theory of such systems where the helical order is destabilized in favor of…

Strongly Correlated Electrons · Physics 2008-04-12 I. Fischer , N. Shah , A. Rosch

Spontaneous onset of a low temperature topologically ordered phase in a 2-dimensional (2D) lattice model of uniaxial liquid crystal (LC) was debated extensively pointing to a suspected underlying mechanism affecting the RG flow near the…

Soft Condensed Matter · Physics 2021-06-29 B. Kamala Latha , Surajit Dhara , V. S. S. Sastry

We propose quantum phase transitions beyond the Landau's paradigm of Sp(4) spin Heisenberg models on the triangular and square lattices, motivated by the exact Sp(4)$\simeq$ SO(5) symmetry of spin-3/2 fermionic cold atomic system with only…

Strongly Correlated Electrons · Physics 2008-11-26 Yang Qi , Cenke Xu

We analyze the early phase of brine entrapment in sea ice, using a phase field model. This model for a first-order phase transition couples non-conserved order parameter kinetics to salt diffusion. The evolution equations are derived from a…

Atmospheric and Oceanic Physics · Physics 2014-05-05 Silke Thoms , Bernd Kutschan , Klaus Morawetz

Recent experiments probing a new ferroelectric liquid crystal (CLF08) confined in cells with planar alignment have shown dielectric and optic anomalies suggesting the onset of ferrielectric ordering within the surface lattice of…

Soft Condensed Matter · Physics 2016-04-20 B. Mettout , H. Pasco Logbo , Y. Gagou , H. Vasseur , P. Gisse

An extension to a high-order model for the direct isotropic/smectic-A liquid crystalline phase transition was derived to take into account thermal effects including anisotropic thermal diffusion and latent heat of phase-ordering.…

Soft Condensed Matter · Physics 2009-09-29 Nasser Mohieddin Abukhdeir , Alejandro D. Rey

In accordance with recent experiments the mean-field type theories predict the presence of numerous metastable minima (states) in the rugged free-energy landscape of frustrated disordered magnets. This multiplicity of long-lived states with…

Disordered Systems and Neural Networks · Physics 2015-05-14 P. N. Timonin

We propose the Landau model for lock-in phase transitions in uniaxially modulated improper ferroelectric incommensurate-commensurate systems of class I. It includes Umklapp terms of third and fourth order and secondary order parameter…

Materials Science · Physics 2009-10-31 M. Latkovic , A. Bjelis , V. Dananic

We show that Landau theory for the isotropic, nematic, smectic A, and smectic C phases generically, but not ubiquitously, implies de Vries behavior. I.e., a continuous AC transition can occur with little layer contraction; the birefringence…

Soft Condensed Matter · Physics 2009-11-11 Karl Saunders , Daniel Hernandez , Staci Pearson , John Toner

Landau theory is used to investigate the behaviour of a metallic magnet driven towards a quantum critical point by the application of pressure. The observed dependence of the transition temperature with pressure is used to show that the…

Statistical Mechanics · Physics 2015-05-14 Gillian A Gehring , Mahrous R. Ahmed

The phenomenological Landau-de Gennes (LdG) model is a powerful continuum theory to describe the macroscopic state of nematic liquid crystals. However, it is invariably less accurate and less physically informed than the molecular-level…

Soft Condensed Matter · Physics 2024-11-20 Baoming Shi , Apala Majumdar , Lei Zhang

Metastability is a quintessential feature of first order quantum phase transitions, which is lost either by dynamical instability or by nucleating bubbles of a true vacuum through quantum tunneling. By considering a drive across the first…

Statistical Mechanics · Physics 2021-07-28 Aritra Sinha , Titas Chanda , Jacek Dziarmaga

Transition from bending-dominated to stretching-dominated elastic response in semi-flexible fibrous networks plays an important role in the mechanical behavior of cells and tissues. It is induced by changes in network connectivity and…

Soft Condensed Matter · Physics 2019-11-13 O. U. Salman , G. Vitale , L. Truskinovsky

The polarization and density modulation associated with antiferroelectric ordering is studied experimentally as a function of temperature in two ferroelectric nematic liquid crystals, the prototypical single compound (DIO) and a commercial…