Dynamic Ginzburg-Landau Theory for the Liquid-Solid Phase Transition

1980 ◽  
Vol 35 (1) ◽  
pp. 69-74
Author(s):  
S. Hess
Keyword(s):  
Phase Transition ◽  
Entropy Production ◽  
Order Parameter ◽  
Landau Theory ◽  
Constitutive Law ◽  
Relaxation Equation ◽  
Ginzburg Landau ◽  
Specific Internal Energy ◽  
Nonlinear Relaxation ◽  
Anisotropy Tensor

Abstract The anisotropy of the probability distribution function for the unit vector joining two nearest neighbour atoms is characterized by tensorial order parameters. For cubic symmetry, the most relevant tensor is of rank 4. Starting from an ansatz for the dependence of the (specific) internal energy, volume and entropy; the entropy production is calculated which is caused by a temporial change of the 4-th rank anisotropy tensor. A constitutive law which guarantees that the entropy production is positive leads to a nonlinear relaxation equation. It shows the features typical for a dynamic Ginzburg-Landau theory. The linearized version of the relaxation equation contains an effective relaxation time and a correlation length which exhibit a temperature dependence typical for a mean field theory. For a special case where the anisotropy tensor can be characterized by a scalar order parameter, the nonlinear relaxation equation is studied in some detail. Its stationary and spatially homogeneous solutions are zero and nonzero values for the order parameter depending on whether the temperature T is larger or smaller than the transition temperature. The unordered phase corresponds to a liquid state, the ordered phase to a simple or body centered cubic crystal. The phase transition is of 1st order. There exist also metastable states.

Static and dynamical elastic behavior of Lu5Ir4Si10 around its first-order structural phase transition

2020 ◽  
Vol 34 (12) ◽  
pp. 2050116
Author(s):  
M. Saint-Paul ◽  
C. Opagiste ◽  
C. Guttin
Keyword(s):  
Phase Transition ◽  
Theoretical Approach ◽  
Order Parameter ◽  
Landau Theory ◽  
Structural Phase ◽  
Elastic Stiffness ◽  
Elastic Behavior ◽  
Velocity Measurements ◽  
First Order ◽  
First Order Transition

Ultrasonic velocity measurements could be performed on a good quality single crystal of [Formula: see text] around its transition around 80 K. The behavior of the stiffness components demonstrates a first-order transition. The temperature dependence of the longitudinal elastic stiffness components [Formula: see text] and [Formula: see text] can be analyzed by the classical Landau theory and assuming a stricter coupling between the strain and the order parameter. A theoretical approach and experimental results are discussed.

scholarly journals Specific heat jump of two-band superconductor KFe2As2 using Ginzburg-Landau theory

2014 ◽  
Vol 32 (3) ◽  
pp. 465-469 ◽  
Author(s):  
I. Askerzade
Keyword(s):  
Specific Heat ◽  
Order Parameter ◽  
Landau Theory ◽  
Energy Functional ◽  
Order Parameters ◽  
Ginzburg Landau ◽  
Specific Heat Jump ◽  
Nonlinear Temperature Dependence ◽  
Nonlinear Temperature ◽  
Good Agreement

AbstractIn this study specific heat jump using two-gap Ginzburg-Landau (GL) theory has been calculated. In contrast to the previous approaches, we have taken into account intergradient order parameters interaction in the GL free energy functional. The thermodynamic magnetic field revealed nonlinear temperature dependence due to interband interaction between order parameters and their gradients. The calculations showed that the specific heat jump in two-order parameter superconductors was smaller than that of single-order parameter superconductors. It has been shown that such a model is in good agreement with experimental data for KFe2As2 superconductors.

s-Wave holographic superconductor in different ensembles and its thermodynamic consistency

2017 ◽  
Vol 26 (04) ◽  
pp. 1750027
Author(s):  
Lei Yin ◽  
Defu Hou
Keyword(s):  
Order Parameter ◽  
Helmholtz Free Energy ◽  
Canonical Ensemble ◽  
Landau Theory ◽  
Equation Of Motion ◽  
Superconducting Phase ◽  
S Wave ◽  
Holographic Superconductor ◽  
Thermodynamic Relation ◽  
Ginzburg Landau

In this paper, we analytically study the consistency between the Ginzburg–Landau theory of the holographic superconductor in different ensembles and the fundamental thermodynamic relation, we derive the equation of motion of the scalar field which depicts the superconducting phase in canonical ensemble (CE) and a consistent formula to connect the holographic order-parameter to the Ginzburg–Landau coefficients in different thermodynamic ensembles, and we also study the spatially nonuniform Helmholtz free energy.

scholarly journals A note on the phase transition in a topologically massive Ginzburg-Landau theory

1998 ◽  
Vol 41 (5) ◽  
pp. 547-552 ◽  
Author(s):  
A. P. C Malbouisson ◽  
F. S Nogueira ◽  
N. F Svaiter
Keyword(s):  
Phase Transition ◽  
Landau Theory ◽  
Ginzburg Landau

scholarly journals Multi-mode excitation drives disorder during the ultrafast melting of a C4-symmetry-broken phase

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Daniel Perez-Salinas ◽  
Allan S. Johnson ◽  
Dharmalingam Prabhakaran ◽  
Simon Wall
Keyword(s):  
Phase Transitions ◽  
Order Parameter ◽  
Landau Theory ◽  
Mean Field ◽  
Atomic Scale ◽  
Time Dependent ◽  
Ginzburg Landau ◽  
Mode Excitation ◽  
The Mean ◽  
Multi Mode

AbstractSpontaneous C4-symmetry breaking phases are ubiquitous in layered quantum materials, and often compete with other phases such as superconductivity. Preferential suppression of the symmetry broken phases by light has been used to explain non-equilibrium light induced superconductivity, metallicity, and the creation of metastable states. Key to understanding how these phases emerge is understanding how C4 symmetry is restored. A leading approach is based on time-dependent Ginzburg-Landau theory, which explains the coherence response seen in many systems. However, we show that, for the case of the single layered manganite La0.5Sr1.5MnO4, the theory fails. Instead, we find an ultrafast inhomogeneous disordering transition in which the mean-field order parameter no longer reflects the atomic-scale state of the system. Our results suggest that disorder may be common to light-induced phase transitions, and methods beyond the mean-field are necessary for understanding and manipulating photoinduced phases.

scholarly journals Spontaneous symmetry breaking in the late Universe and glimpses of the early Universe phase transitions à la baryogenesis

2021 ◽  
Author(s):  
M. Sami ◽  
Radouane Gannouji
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Symmetry Breaking ◽  
Spontaneous Symmetry Breaking ◽  
Particle Physics ◽  
Landau Theory ◽  
Bubble Nucleation ◽  
Beyond The Standard Model ◽  
Electroweak Phase Transition ◽  
Ginzburg Landau

Spontaneous symmetry breaking is the foundation of electroweak unification and serves as an integral part of the model building beyond the standard model of particle physics and it also finds interesting applications in the late Universe. We review development related to obtaining the late cosmic acceleration from spontaneous symmetry breaking in the Universe at large scales. This phenomenon is best understood through Ginzburg–Landau theory of phase transitions which we briefly describe. Hereafter, we present elements of spontaneous symmetry breaking in relativistic field theory. We then discuss the “symmetron” scenario-based upon symmetry breaking in the late Universe which is realized by using a specific form of conformal coupling. However, the model is faced with “NO GO” for late-time acceleration due to local gravity constraints. We argue that the problem can be circumvented by using the massless [Formula: see text] theory coupled to massive neutrino matter. As for the early Universe, spontaneous symmetry breaking finds its interesting applications in the study of electroweak phase transition. To this effect, we first discuss in detail the Ginzburg–Landau theory of first-order phase transitions and then apply it to electroweak phase transition including technical discussions on bubble nucleation and sphaleron transitions. We provide a pedagogical exposition of dynamics of electroweak phase transition and emphasize the need to go beyond the standard model of particle physics for addressing the baryogenesis problem. Review ends with a brief discussion on Affleck–Dine mechanism and spontaneous baryogenesis. Appendixes include technical details on essential ingredients of baryogenesis, sphaleron solution, one-loop finite temperature effective potential and dynamics of bubble nucleation.

scholarly journals Topological Frustration can modify the nature of a Quantum Phase Transition

2021 ◽  
Author(s):  
Vanja Marić ◽  
Gianpaolo Torre ◽  
Fabio Franchini ◽  
Salvatore Giampaolo
Keyword(s):  
Phase Transition ◽  
Phase Transitions ◽  
Quantum Phase Transition ◽  
Landau Theory ◽  
Continuous Phase ◽  
Quantum Systems ◽  
Quantum Phase ◽  
Local Order ◽  
Ginzburg Landau ◽  
One Dimensional

Abstract Ginzburg-Landau theory of continuous phase transitions implicitly assumes that microscopic changes are negligible in determining the thermodynamic properties of the system. In this work we provide an example that clearly contrasts with this assumption. In particular, we consider the 2-cluster-Ising model, a one-dimensional spin-1/2 system that is known to exhibit a quantum phase transition between a magnetic and a nematic phase. By imposing boundary conditions that induce topological frustration we show that local order is completely destroyed on both sides of the transition and that the two thermodynamic phases can only be characterized by string order parameters. Having proved that topological frustration is capable of altering the nature of a system's phase transition, this result is a clear challenge to current theories of phase transitions in complex quantum systems.

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