共查询到20条相似文献,搜索用时 0 毫秒
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Using a density dependent quark mass to express non-perturbative interaction effects, we calculate the critical density for a phase transition between nuclear and quark matter atT=0. 相似文献
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B. Kmpfer 《Annalen der Physik》2000,9(8):605-635
The sequence of phase transitions during the hot history of the universe is followed within a phenomenological framework. Particular emphasis is put on the QCD confinement transition, which is at reach under earth laboratory conditions. A tepid inflationary scenario on the GUT scale with bubble growth at moderate supercooling is discussed. 相似文献
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Using the global fiber bundle model as a tractable scheme of progressive fracture in heterogeneous materials, we define the branching ratio in avalanches as a suitable order parameter to clarify the order of the phase transition occurring at the collapse of the system. The model is analyzed using a probabilistic approach suited to smooth fluctuations. The branching ratio shows a behavior analogous to the magnetization in known magnetic systems with second-order phase transitions. We obtain a universal critical exponent beta approximately = 0.5 independent of the probability distribution used to assign the strengths of individual fibers. 相似文献
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Masperi L 《Physical review D: Particles and fields》1990,41(10):3263-3266
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We study chiral symmetry structure at finite density and temperature in the presence of external magnetic field and gravity,
a situation relevant in the early Universe and in the core of compact stars. We then investigate the dynamical evolution of
phase transition in the expanding early Universe and possible formation of quark nuggets and their survival. 相似文献
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A. M. Farutin 《Journal of Experimental and Theoretical Physics》2009,108(3):469-476
Within the Landau theory, phase diagrams are obtained for second-order phase transitions with order parameter in the form of a symmetric traceless tensor of rank at most six that is transformed in accordance with a one-dimensional representation of a crystal group. The case of two-dimensional representation is analyzed for rank equal to three. 相似文献
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We discuss the quantum phase transitions (QPT) in N-spin chains from the point of view of collective observables. We show that the measurement space representation is a convenient tool for the analysis of phase transitions, allowing the determination of an appropriate set of macroscopic order parameters (for a given Hamiltonian). Quantum correlations in the vicinity of the critical points are analyzed both in the ground states and low temperature thermal states. 相似文献
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Dominique Weigel 《Phase Transitions》2013,86(1-4):341-349
there are two types of Commensurate-Incommensurate Phase Transitions : tI between the basic structure and the incommensurate phasis and tL between the inc. phasis and the lock in phasis. They both have connected structures. So that, they must verify the relation between crystallographic groups in accordance with Landau's Theory. But we have to consider the three phases in the superspace - as we do at an ordered-disordered magnetic transition-because the inc. phasis ins't a crystal in the physical space; e.g., in order to cancel the “middle range order” of the inc. phasis at tI, we are led to assume the grey (point) group to the basic structure in the superspace. Now both inc. phase and basic structure verify the connection between point-groups in the superspace in the same way as both para and ferro phases do at a ferroic transition in the physical space. We also show that the same type of relation is possible at tL and we give the order parameter at both tI and tL. 相似文献
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The effect of inhomogeneous fluctuations on instabilities in various nonlinear chemical models is studied in terms of concepts developed in the theory of equilibrium phase transitions.Chercheur qualifié au Fonds National de la Recherche Scientifique. 相似文献
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S. M. Shapiro 《Applied Physics A: Materials Science & Processing》2010,99(3):543-548
Results of lattice dynamics, or atomic motions in a solid, explain many of the thermodynamic properties of solids. Inelastic
neutron scattering conveniently explores the atomic motions, quantized as phonons. Of particular interest are materials that
undergo structural phase transitions. The soft mode theory has been successful in relating anomalous phonon behavior to structural
changes in solids. One such example is the ferromagnetic shape memory alloy, Ni2MnGa, which undergoes a sequence of phase transitions leading to a magnetic, incommensurate modulated, tetragonal phase as
the ground state. The experiments, coupled with first principles calculations, provide evidence that strong electron–phonon
coupling is the driving mechanism of the phase transformation. 相似文献
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简单介绍了文章作者在半导体硅重构表面及其相变动力学研究方面的进展.近期Si(111) (7×7)-(1×1)相变的实验研究发现,将温度升高到相变温度以上时,7×7岛面积以恒定的衰减速率随时间减小至零,且初始面积越大的岛这个衰减速率就越大.文章作者分析了大量的实验事实,由此提出了一个双速相场模型来解释这个重要而令人困惑的现象.模型重点是:在相变过程中,7×7关键结构变化较快,随后的层错消解过程要慢得多.这个模型完美地解释了相关实验现象,说明该模型抓住了关键物理要素,这种相场方法也可以用于其他半导体表面相变研究. 相似文献
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We provide an overview of some modern developments in the theory of phases and phase transitions in classical and quantum systems. We show the link between non-ergodicity and fidelity in quantum systems and discuss topological phase transitions. We show that the quantum phase transitions are associated with qualitative changes in some properties of the quantum wavefunctions across the phase transition. We discuss the topological phase transition associated with p-wave superconductor since it is a topic of wide interest because of the possible observation of Majorana fermions. 相似文献
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