Second and first order phase transition analogy in the operation of an organic dye laser

By an extension of the Landau theory of phase transitions for the case of an organic dye laser, it is shown that the threshold behavior of such a laser may be interpreted as an example of a second or first order phase transition. The character of the phase transition primarily depends on the wavelength dependent internal reabsorption of the laser light, which can be controlled by simple wavelength tuning of the dye laser.     

Non-equilibrium charge transport at a first-order phase transition

We have studied penetration of a charge density disturbance cause by a moving bubble wall in relativistic plasma, using the self-consistent field approximation. We have shown that the charge density as a function of distance from the wall has a power-law tail 1/z². We find that penetration of charge in plasma is most effective when the wall velocity is close to unity. However, for wall velocities u0.7, the effective, in the integral sense, penetration length is found to be essentially equal to the static Debye radius.     

Hydrodynamical description of a hadron-quark first-order phase transition

Solutions of hydrodynamical equations are presented for the equation of state of the Van der Waals type allowing for a first-order phase transition. As an example we consider the hadron-quark phase transition in heavy-ion collisions. It is shown that fluctuations dissolve and grow as if the fluid is effectively very viscous. In the vicinity of the critical point even in spinodal region seeds are growing slowly due to viscosity, surface tension and critical slowing down. These non-equilibrium effects prevent enhancement of fluctuations in the near-critical region, which in thermodynamical approach is frequently considered as a signal of the critical endpoint in heavy-ion collisions.     

Growth of clusters in a first-order phase transition

The results of computer simulations of phase separation kinetics in a binary alloy quenched from a high temperature are analyzed in detail, using the ideas of Lifshitz and Slyozov. The alloy was modeled by a three-dimensional Ising model with Kawasaki dynamics. The temperature after quenching was 0.59T _c, whereT _c is the critical temperature, and the concentration of minority atoms was=0.075, which is about five times their largest possible single-phase equilibrium concentration at that temperature. The time interval covered by our analysis goes from about 1000 to 6000 attempted interchanges per site. The size distribution of small clusters of minority atoms is fitted approximately byc ₁(1-)³ w(t),c ₁ (1–)⁴ Q _l w(t)^l(2l10); wherec _l is the concentration of clusters of sizel;Q ₂,...,Q ₁₀ are known constants, the cluster partition functions;t is the time; andw(t)=0.015(1+7.17t ^–1/3). The distribution of large clusters (l20) is fitted approximately by the type of distribution proposed by Lifshitz and Slyozov,c _l ,(t)=–(d/dl) [lnt+p (l/t)], where is a function given by those authors and is defined by(x)=C _o e–x-C ₁ e ^–4x/3-C ₂ e ^–5x/3;C ₀,C ₁,C ₂ are constants determined by considering how the total number of particles in large clusters changes with time.Supported by the U.S. Air Force Office of Scientific Research under Grant No. 78-3522 and by the U.S. Department of Energy under Contract No. EY-76-C-02-3077*000.     

Complete inheritance of fractal properties during first-order phase transition

We present experimental evidence of complete fractal properties inheritance in the course of first-order phase transition from amorphous to monoclinic or tetragonal zirconia under hydrothermal conditions. This phenomenon takes place either under rapid microwave heating or conventional heating regardless of starting fractal dimension value. Exactly the same effect is observed for hafnia. The similarity of the local structures of amorphous and crystalline zirconia as well as relatively soft crystallization conditions could be the definite reasons for the conservation of the mesostructure in the course of phase transition.     

Gauge field fluctuations and first-order phase transition in color superconductivity

We study the gauge field fluctuations in dense quark matter and determine the temperature of the induced first-order phase transition to the color-superconducting phase in weak coupling. We find that the local approximation of the coupling between the gauge potential and the order parameter, employed in the Ginzburg-Landau theory, has to be modified by restoring the full momentum dependence of the polarization function of gluons in the superconducting phase.     

Hysteresis and first-order phase transition in the two-dimensional electron gas

We report experimental evidence of the first-order phase transitions in the two-dimensional electron gas formed in a gated wide GaAs/AlGaAs quantum well at even-integer quantum-Hall states. At the filling factor values of ν=2,4 and low temperatures, crossing of Landau levels through the application of the gate bias yields a suppression of the quantum-Hall-state excitation gap and hysteretical behaviour of the diagonal resistivity in up and down sweeps of the magnetic field. Detailed many-body calculations indicate the occurrence of a first-order phase transition and allow the determination of the exact properties of the electron ground states involved in the transition.     

Cluster structure and the first-order phase transition in dipolar systems

The European Physical Journal E - The Monte Carlo technique is used to simulate a 3D dipolar hard-sphere system. The spatial and magnetic structure of clusters formed by magnetic dipolar...     

A first-order level-2 phase transition in thermodynamic formalism

We show the existence of a phase transition at the level of measures for the generalized dimension of the maximal entropy measure in a model that was considered by F. Hofbauer and which is related to a model of M. Fisher. The model presented here is related to the one-dimensional Ising model in which a wall effect is assumed. In this situation, the problem has to be considered in the one-dimensional lattice . In general there is no first-order transition for the Ising model in the lattice , but under our assumptions such transitions can occur. The Ising model has the purpose of explaining the magnetization of ferromagnetic systems at low temperatures. The main difference of our result from a previous result of F. Hofbauer is that the transition is analyzed in the setting of the generalized dimension. This setting is more closely related to the observables. The main purpose of this paper is to explain another mathematical model for phase transition using the mathematical results obtained by F. Hofbauer. We also use results of the thermodynamic formalism in an essential way.     

Hydrogen embrittlement under load as a first-order phase transition

The stress-strain equation of state for a material with dissolved hydrogen is derived within a two-component continuum model. It is demonstrated that, for the parameters corresponding to conventional metals, it has the shape of a loop similar to the van der Waals loop. On this basis, it is concluded that hydrogen embrittlement of materials under load is a typical first-order phase transition and, therefore, occurs through nucleation of a new phase. Thermodynamic and kinetic theories of this transition are developed, and time dependences of all the main characteristics of this process are calculated.     

Field-dependence of the first-order phase transition in terbium phosphide

Magnetization measurements confirm the presence of a strong quadrupolar coupling between the Tb³⁺, responsible for the discontinuous nature of the transition, and show a reduction of T_N proportional to H². This behaviour contrasts with recent renormalization-group predictions for TbP, but can be quantitatively explained within a mean-field model.     

Energy budget of cosmological first-order phase transition in FLRWbackground

We study the hydrodynamics of bubble expansion in cosmological first-order phase transition in the Friedmann-Lema??treRobertson-Walker(FLRW) background with probe limit. Different from previous studies for fast first-order phase transition in flat background, we find that, for slow first-order phase transition in FLRW background with a given peculiar velocity of the bubble wall, the efficiency factor of energy transfer into bulk motion of thermal fluid is significantly reduced, thus decreasing the previously-thought dominated contribution from sound wave to the stochastic gravitational-wave background.     

Interfacial adsorption phenomena at a weakly first-order phase transition

We study the interfacial adsorption phenomena of the ferromagnetic five-state Potts model on the square lattice, whose transition is of weakly first-order, by using Monte Carlo simulations and finite-size scaling theory. It is shown that the net-adsorption has a finite-size effect according to the first-order phase transition even for systems much smaller than the bulk correlation length.     

Finite-size effects on nucleation in a first-order phase transition

We discuss finite-size effects on homogeneous nucleation in first-order phase transitions. We study their implications for cosmological phase transitions and to the hadronization of a quark–gluon plasma generated in high-energy heavy ion collisions. Very general arguments allow us to show that the finite size of the early universe has virtually no relevance in the process of nucleation and in the growth of cosmological bubbles during the primordial quark–hadron and the electroweak phase transitions. In the case of high-energy heavy ion collisions, finite-size effects play an important role in the late-stage growth of hadronic bubbles.     

A first-order phase transition in a three-dimensional vertex model

For a specific three-dimensional vertex model, it is proven that it will show a first-order phase transition. The critical temperature is given in terms of the energy of some local vertex configurations. The approach used is similar to the Nagle approach. Some classes of compounds are considered which may be related to this model.     

Evolution of order and chaos across a first-order quantum phase transition

We study the evolution of the dynamics across a generic first-order quantum phase transition in an interacting boson model of nuclei. The dynamics inside the phase coexistence region exhibits a very simple pattern. A classical analysis reveals a robustly regular dynamics confined to the deformed region and well separated from a chaotic dynamics ascribed to the spherical region. A quantum analysis discloses regular bands of states in the deformed region, which persist to energies well above the phase-separating barrier, in the face of a complicated environment. The impact of kinetic collective rotational terms on this intricate interplay of order and chaos is investigated.     

Gravitational waves from cosmic strings after a first-order phase transition

We study the possibility of probing high scale phase transitions that are inaccessible by LIGO. Our study shows that the stochastic gravitational-wave radiation from cosmic strings that are formed after the first-order phase transition can be detected by space-based interferometers when the phase transition temperature is \begin{document}$ T_n\sim {\cal{O}}(10^{8-11}) $\end{document} GeV.