Phase transition phenomenon: A compound measure analysis

Jamming transition of high-dimensional traffic dynamics

The effects of temperature and frequency dispersion on sound speed in bulk poly (vinyl alcohol) poly (N-isopropylacrylamide) hydrogels caused by the phase transition

Percolation on interdependent networks with cliques and weak interdependence

VO2, which exhibits semiconductor-metal phase transition characteristics occurring on a picosecond time scale, holds great promise for ultrafast terahertz modulation in next-generation communication. However, as of now, there is no reported prototype for an ultrafast device. The temperature effect has been proposed as one of the major obstacles. Consequently, reducing the excitation threshold for the phase transition would be highly significant. The traditional strategy typically involves chemical doping, but this approach often leads to a decrease in phase transition amplitude and a slower transition speed. In this work, we proposed a design featuring a highly conductive MXene interfacial layer between the VO2 film and the substrate. We demonstrate a significant reduction in the phase transition threshold for both temperature and laser-induced phase transition by adjusting the conductivity of the MXene layers with varying thicknesses. Our observations show that the phase transition temperature can be decreased by 9 °C, while the pump fluence for laser excitation can be reduced by as high as 36%. The ultrafast phase transition process on a picosecond scale, as revealed by the optical-pump terahertz-probe method, suggests that the MXene layers have minimal impact on the phase transition speed. Moreover, the reduced phase transition threshold can remarkably alleviate the photothermal effect and inhibit temperature rise and diffusion in VO2 triggered by laser. This study offers a blueprint for designing VO2/MXene hybrid films with reduced phase transition thresholds. It holds significant potential for the development of low-power, intelligent optical and electrical devices including, but not limited to, terahertz modulators based on phase transition phenomena.

Recently, the dynamics of quantum systems that involve both unitary evolution and quantum measurements have attracted attention due to the exotic phenomenon of measurement-induced phase transitions. The latter refers to a sudden change in a property of a state of n qubits, such as its entanglement entropy, depending on the rate at which individual qubits are measured. At the same time, quantum complexity emerged as a key quantity for the identification of complex behaviour in quantum many-body dynamics. In this work, we investigate the dynamics of the quantum state complexity in monitored random circuits, where n qubits evolve according to a random unitary circuit and are individually measured with a fixed probability at each time step. We find that the evolution of the exact quantum state complexity undergoes a phase transition when changing the measurement rate. Below a critical measurement rate, the complexity grows at least linearly in time until {saturating to a value eΩ(n).} Above, the complexity does not exceed poly⁡(n). In our proof, we make use of percolation theory to find paths along which an exponentially long quantum computation can be run below the critical rate, and to identify events where the state complexity is reset to zero above the critical rate. We lower bound the exact state complexity in the former regime using recently developed techniques from algebraic geometry. Our results combine quantum complexity growth, phase transitions, and computation with measurements to help understand the behavior of monitored random circuits and to make progress towards determining the computational power of measurements in many-body systems.

In this present work, nanocrystalline powders of Pb-doped LaMnO3 or La0.64Pb0.36MnO3 (LPMO) have been synthesized with various grain sizes by a solid-state reaction method followed by ball milling technique. Based on the dependence of crystallite size, the magnetic properties of the LPMO nanoperovskites have been investigated. The nanoperovskites have been structurally characterized. Further, the synthesized nanoperovskite manganite materials with various grain sizes are systematically studied for ultrasonic longitudinal velocity (UL), shear velocity (US) and longitudinal and shear attenuation (αL and αS) in wide range of temperatures. All the nanoperovskites revealed an anomalous behaviour in concern with ultrasonic velocities and attenuation towards the phenomenon of phase transition.

We present an equation of state for mildly coupled ions in ultra-cold neutral (UCN) plasmas. By introducing the mean field approximation, we obtain expressions for free energy and pressure of ions. It is found that below a critical temperature, the ions undergo a first-order phase transition and exist in a mixed vapor–liquid phase for a range of values of the ion Coulomb coupling parameter Γi (= the ion Coulomb energy/the ion kinetic energy), and in a mildly coupled liquid state for values of Γi above this range. Our analytical results demonstrate that the phenomena of phase transitions, as reported herein, are relevant for the existing computer simulations and are expected to be observed in the forthcoming UCN laboratory plasma experiments.

BackgroundPhase transition and phase separation as well as their tipping points are penetrating phenomena in biology and are intrinsic properties of biological systems ranging from basic molecule complexes to cells and all way up to entire ecosystems.ResultsFor example, phase separation has been established as a key mechanism for biological molecules such as protein or RNA to form membraneless organelles to perform complex biological functions. Phase transitions are commonly observed during cellular differentiation, and generally, there are the tipping points or critical states just before the phase transitions. And the stability of ecosystem and extinction of species are systematic manifestation of phase transitions. All phase transition and phase separation phenomena display switch‐like behavior and critical transitions.ConclusionHere we summarize the concepts regarding the epithelial‐to‐mesenchymal transition (EMT) as a type of phase changes and the implication of critical transitions in EMT, and discuss open questions and challenges in this fast‐moving field.

Two-dimensional (2D) materials have emerged as a forefront of research in materials science, driven by their exceptional and diverse properties. These materials, often with atomic thickness, exhibit phase transitions with small energy barrier, which can enable the development of energy-efficicient devices. Understanding these phase transitions is not only a fascinating scientific endeavor but also crucial for technological innovation. In this presentation, we will cover phase transitions in 2D materials, encompassing both intralayer and interlayer phenomena. We will dissect the mechanisms by which phase transitions can radically modify the electrical, optical, and mechanical properties of these materials, and discuss the engineering approaches designed to control energy barrier and transition process. Special attention will be given to the devices developed from phase transition phenomena in 2D materials, highlighting their potential applications in the realms of memory storage and sensory technology.

In a Multi-Agent System (MAS), there usually exist system-level goals that agents are collectively trying to attain. Generally speaking, the local behaviours and performances of individual agents directly determine which global characteristics of an MAS, for example, the global performance and/or patterns, will emerge and how the system-level goals will be attained. In most cases, such a local?global relationship is neither obvious nor straightforward. In this paper, we will address several issues on modelling emergent complex behaviours in MAS. In particular, we will focus on the local?global relationship in a Self-Organising MAS (SOMAS), and discuss the phenomena of Self-Organised Criticality (SOC) and phase transition in SOMAS.

We investigate the medium-induced change of mass and width of $J/\ensuremath{\psi}$ and ${\ensuremath{\eta}}_{c}$ across the phase transition in hot gluonic matter using QCD sum rules. In the QCD sum rule approach, the medium effect on heavy quarkonia is induced by the change of both scalar and twist-2 gluon condensates, whose temperature dependencies are extracted from the lattice calculations of energy density and pressure. Although the stability of the operator product expansion side seems to break down at $Tg1.06{T}_{c}$ for the vector channel and $Tg1.04{T}_{c}$ for the pseudoscalar channel, we find a sudden change of the spectral property across the critical temperature ${T}_{c}$, which originates from an equally rapid change of the scalar gluon condensate characterized by $\ensuremath{\varepsilon}\ensuremath{-}3p$. By parametrizing the ground state of the spectral density by the Breit-Wigner form, we find that for both $J/\ensuremath{\psi}$ and ${\ensuremath{\eta}}_{c}$, the masses suddenly decrease maximally by a few hundreds of MeV and the widths broaden to $~100$ MeV slightly above ${T}_{c}$. The implications for recent and future heavy-ion experiments are discussed. We also carry out a similar analysis for charmonia in nuclear matter, which could serve as a testing ground for observing the precursor phenomena of the QCD phase transition. We finally discuss the possibility of observing the mass shift at nuclear matter at the FAIR project at GSI.

We study the thermodynamics of higher-dimensional singly spinning asymptotically AdS black holes in the canonical (fixed J) ensemble of extended phase space, where the cosmological constant is treated as pressure and the corresponding conjugate quantity is interpreted as thermodynamic volume. Along with the usual small/large black hole phase transition, we find a new phenomenon of reentrant phase transitions for all d>5 dimensions, in which a monotonic variation of the temperature yields two phase transitions from large to small and back to large black holes. This situation is similar to that seen in multicomponent liquids.

The phenomena of the first order phase transition (two-dimensional melting) of grain boundary at temperatures 0.6 - 0.9 TS0 (of the solid state melting point), discovered by the author (1971), is a fundamental property of solid crystalline materials. This finding leads to a principal revision of the scientific concepts of the solid state of substance. The phenomenological description and justification of the finding are developed. The generalized equation of Clausius-Clapeyron type for two-dimensional phase transition was obtained by applying the mathematical tools of the film thermodynamics. The equation has been used for calculating the grain boundary phase transition(GBPhT) temperature TSf of any metal, which TSf value lies within the range of (0.55 - 0.86) TS0. The investigation outcomes are applied to develop the methodology for more effective hard coating formation by synthesis of nanosize nitrides and carbonitrides in surface layers of steels and nickel alloys using a thermo-chemical processing (TChP). Production of an overall nitrogen concentration gradient from 4% to 0.5% at within surface layers leads to formation of modified coatings with a stepped change in properties. The mechanical behavior of new tools at the industrial tests indicated a higher heat resistance (nickel alloys), high resistance to surface wears and fragile breaks-down (chromium tool steels). A short overview of the results of some graded alloys characterization is presented.

The crystallization behaviour of pure 1,4‐trans‐poly(butadiene) (1,4‐PTBD) from dilute solutions in heptane and its relation to the phase transition phenomena in the solid state is investigated. Depending on whether the nucleation occurs in the high‐temperature modification II or the low‐temperature modification I two different regimes of crystallization behaviour are observed which in turn determine the crystal thickness as well as the phase transition and annealing behaviour of the crystals. The equilibrium phase transition temperature (I–II) is 356 K, the corresponding enthalpy is 144 J.g−1; the equilibrium melting temperature is 437 K and the enthalpy of melting is 69 J.g−1. The surface free energy terms are obtained relating the crystal thicknesses measured by SAXS and DSC to the temperatures of phase transition and melting, resp. Following Hoffman's theory of nucleation and growth the theoretical curves for the rate of nucleation and crystal growth are calculated and compared to the experimental results.

The dynamics of unit-charged graphs under iterated local majority rule observed in Moran [2] strongly suggested to me a phase-transition phenomenon. In a correspondence with D. Ruelle on this matter in late 1993, he expressed his feelings that the connection was too vague and that temperature was absent in it. This note is a reproduction of my 1993 response, where I try to force my suggestive feelings into a bit more formal frame. A recent work of Yuval Ginosar and Ron Holzman [1], which extends Moran [2], allows us to replace the definition of a solid, given in section 4, by a sharper one, namely that of a “puppet” in their terminology. This means that in section 4 we may define a G ∈ Y to be a solid if every initial charge upon it decays under these dynamics—possibly in infinite time—into a time-periodic charging of a time period not longer than two. This note suggests an approach to the phenomenon of phase transition based on the behaviour of some cellular automata on infinitely countable nets, as noted recently in Moran [2]. Specifically, we use a majority automaton operating simultaneously on a countably infinite graph as a test device determining its “phase.” Results in Moran [2] suggest some sharp partition of a configuration space made up of the totality of such graphs into “solids,” where the only periods allowed for the automaton are 1 or 2, versus the others. Results in Moran [2] allow also the introduction of a “temperature” functional—a numerical parameter defined for each configuration, with the property that a configuration is “solid” whenever its “temperature” is negative. We first describe a possible physical interpretation of such a model, taking the nodes of a graph to be “particles” (stars, electrons, ions, atoms, molecules, radicals—as the case may be) in some Riemannian manifold. Our interpretation is obviously open to a wide diversity of modifications. It is hoped that in spite of its admittedly speculative nature, it may invoke a novel approach to the theoretical treatment of phase transition.