共查询到20条相似文献,搜索用时 125 毫秒
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采用Monte Carlo方法对3DX-Y模型进行数值模拟计算,研究了在非线性外场驱动下3DX-Y模 型的滞后标度和动态相变.得出了滞后标度关系为Area~hα0ωβ(1-T/Tc)γ, 其中α=0.57,β=0.34,γ=0.90.发现其动态相变行为在一定的临界参数条件下,初始短周 期(周期数PN≤10)内的结果具有与Ising模型类似的对称性破缺;但在长周期内(PN≥200)的 结果则明显区别于Ising模型而与Heisenberg模型相近,也即无稳定动态有序铁磁相的存在.
关键词:
X-Y模型
滞后标度
动态相变
Monte Carlo方法 相似文献
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我们对SU(3)格点规范理论的两种新作用量进行了Monte Carlo模拟, 计算了元格平均内能和比热. 内能曲线都趋向共同的弱耦合极限, 比热都有峰. 我们观察到了由于格点间隔α的高次幂项不同引起的比热峰明显漂移的现象. 相似文献
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我们对SU(2)群格点规范理论的Sinl-Sin((1/2)TrUp)作用量做了有限温度下的Monte Carlo计算,观察到一个高温下解除禁闭的相变。临界点是Tc≈334±40Mev,这与使用Wilson作用量及其它类型作用量所得结果可以相容。 相似文献
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我们在格点规范场理论的Monte Carlo模拟中引入了一种节省时间的取样方法,研究了该方法在Z2规范群和SU(3)规范群临界点附近的行为,发现在越过一阶相变点时该方法将失效。按一定的程序,此特点可用来寻找一阶相变点。 相似文献
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A. B. Babaev A. K. Murtazaev E. M. Suleimanov T. R. Rizvanova 《Physics of the Solid State》2016,58(10):2074-2077
Influence of disorder in the form of frustration on the thermodynamic behavior of a two-dimensional three-vertex Potts model has been studied by the Monte Carlo method, taking into account the nearest and next-nearest neighbors. Systems with linear sizes of L × L = N (L = 9–48) on a triangular lattice have been considered. It has been shown that in the case of J1 > 0 and J2 < 0 frustrations appear in the spin system within the interval of 0.5 ≤ |r| ≤ 1.0. The model undergoes a phase transition outside this region. 相似文献
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The topological susceptibility χt and the correlation length ξ in the CP2 model on a two-dimensional triangular lattice are calculated by the Monte Carlo simulation method. Using variant lattice actions, we verify the universality of the dimensionless quantity χtξ2 ~- 0.09 in the scaling region, thus indicating the presence of physical topological effects in the scaling limit. As a by-product, we obtain a combinatorial formula for the topological charge. 相似文献
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We define a two parameter lattice field theory which interpolates between the O (2N) Heisenberg model, pure U(1) gauge theory, and a lattice version of the CPN?1 model. The phase diagram in space-time dimension d=4 is obtained by Monte Carlo simulation on a 44 lattice, and the nature of the phases is discussed in mean field approximation. 相似文献
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K.J.M. Moriarty 《Physics letters. [Part B]》1981,102(1):53-54
Monte Carlo simulations of the string tension are calculated for four-dimensional U(1) gauge theory on a 64 lattice. The string tension follows the result -1n(β/2) in the high temperature region and is zero for β > βc, where βc is the critical inverse temperature. 相似文献
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A statistical bond-percolation model for the fragmentation has been applied to the proton-induced reactions assuming a lattice structure to the prefragment nucleus and using the Monte Carlo technique to determine the bond to be broken. The model succeeded to reproduce the essential features of the mass yield curves for the p-Cu reaction at 3.9 GeV and to describe qualitatively the charge and the multiplicity distributions of the projectile fragments for the 28Si interactions with the quasi-free emulsion nucleon at 3.7 AGeV. 相似文献
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The mass of the 0+ glueball in 4-dimensional lattice gauge theory with a mixed SU(2)-SO(3) action is obtained via Monte Carlo. We work in a region far from the critical end point in the phase diagram, with an action partly motivated by renormalization group flows in the Migdal-Kadanoff approximation. A large-N resummation of perturbation theory is used to show that the mass gap scales as predicted by the perturbative renormalization group. Independent of this, our results show that the ratio of the glueball mass to the square root of the string tension, obtained from a previous Monte Carlo, is a renormalization group invariant. 相似文献
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Frank H. Stillinger 《Journal of statistical physics》1976,15(5):407-421
Classical lattice gases consisting of structureless particles (with spin) have been quantized by introducing a kinetic energy operator that produces nearest-neighbor hops. Systematic quantum corrections for the partition function and the particle distribution functions appear naturally as power series inX =
2/2ml
2 (
–1 =k
B
T,m is the mass,l is a distance related to lattice spacing). These corrections require knowledge of certain particle displacement probabilities in the corresponding classical lattice gases. Leading-order corrections have been derived in forms that should facilitate their use in computer simulation studies of lattice gases by the standard Monte Carlo method. 相似文献
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The lattice regularizedSU(2)l ?SU(2)r symmetric scalar fermion model with explicit mirror fermions is investigated in the phase with unbroken symmetry. In the present work numerical Monte Carlo calculations with dynamical fermions are performed on 43·8 and 43·16 lattices near the expected perturbative Gaussian fixed point. The bare Yukawa coupling of the mirror fermion is fixed at zero. Global symmetries of the model are discussed, and the numerical results are supported by lattice perturbation theory. 相似文献
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Gernot Münster 《Physics letters. [Part B]》1980,95(1):59-62
We present results of high temperature expansions up to order g?24 for the vortex free energy respectively string tension in pure lattice gauge theories with gauge groups SU(2) and Z2 in 3 and 4 dimensions. For SU(2) in 4 dimensions the result is compared with Monte Carlo calculations of Creutz and is in good agreement. An intermediate coupling region is seen, where the string tension smoothly interpolates between strong coupling and weak coupling behaviour. 相似文献
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We discuss the recently proposed multicanonical multigrid Monte Carlo method and apply it to the scalar
4 on a square lattice. To investigate the peformance of the new algorithm at the field-driven first-order phase transitions between the two ordered phases we carefully analyze the autocorrelations of the Monte Carlo process. Compared with standard mlticanonical simulations a real-time improvement of about one order of magnitude is established. The interface tension between the two ordered phases is extracted from highstatistics histograms of the magnetization applying histogram reweighting techniques. 相似文献