共查询到20条相似文献,搜索用时 8 毫秒
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采用格点自旋消约方法,将具有最近邻和次近邻耦合作用的镶嵌正方Ising晶格变换成等效的具有最近邻、次近邻和四体耦合作用的正方Ising晶格,得到系统近似解的临界点在K′C=0.4406868.结果表明:在相变点最近邻耦合作用K1和次近邻耦合作用K2之间满足一定关系.如果只计及镶嵌正方Ising晶格的最近邻耦合作用K1,则其严格解的临界点在K1C=0.7635.由此可以推断在正方格点间安放两个自旋的双镶嵌正方Ising晶格,在只计及最近邻耦合作用情况下,也是严格可解的. 相似文献
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The catastrophe theory is applied to investigating the number of permissible phase for homogeneous-isotropic and homogeneous anisotropic Ising lattices. 相似文献
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采用部分格点自旋消约变换,将镶嵌正方晶格上具有最近邻耦合作用K1和次近邻耦合作用K2的Ising模型变换成等效的具有最近邻、次近邻和四体耦合作用的正方Ising晶格.发现系统的临界点在(K1C,K2C)=(0.5125,0.2134),由此决定系统的临界温度,幷讨论了系统的普适性. 相似文献
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应用位置空间重整化群方法,对引入“鬼”场的二维次近邻正方格点渗流模型进行研究,得到临界值Pc和临界指数α,β,γ,ν,δ,η。 相似文献
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Flow behavior of the driven two-dimensional vortex lattice is numerically studied with different densities of randomly distributed pointlike pinning centers. Different features in the curves of velocity-force dependence are found between the elastic and plastic regimes. Scaling fit between force and velocity above the critical driving force can be obtained in the elastic regime but fails in the plastic regime. Transition from the lastic to plastic regimes is accompanied by maximum peaks in the differential curves of velocity-force dependence in the disordered vortex lattice. 相似文献
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With the help of the decimation ansatz of the renormlization group, the dependence of critical temperature on a transverse magnetic field is calculated analytically for a quasi-one-dimensional disordered superconductor model, based on the de Gennes-Skal-Shklovskii (dGSS) picture of the large cluster in a percolation system. Our results are in good agreement with those given by Halley's scaling theory. 相似文献
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THEORETICAL STUDY OF THE GROUND-STATE PROPERTY OF THE TWO-DIMENSIONAL HEISENBERG ANTIFERROMAGNET ON A TRIANGULAR LATTICE 下载免费PDF全文
Within the Tyablikov's theoretical framework, the ground-state property of the two-dimensional antiferromagnetic Heisenberg model on a triangular lattice is studied. Our results show that the sublattice magnetization is M=0.241 and the ground-state energy per bond is Eg/ NZJ =-0.166, which are in agreement with the numerical simulations. 相似文献
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分别给出周期和自由边界条件下求解一维Fibonacci准周期Frustrated Ising模型的配分函数的方法。研究它的低温热力学性质,发现当温度趋于零时,其热力学函数在参数b/J=2/(2m+1)(m为正整数)处发生尖锐的变化。分析了零温时系统在不同参数范围内的基态构形,对计算的结果进行了解释。
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FERRIMAGNETIC PHASES OF THE BLUME-EMERY-GRIFFITHS MODEL AND THE POTTS MODEL ON THE DIAMOND LATTICE 下载免费PDF全文
The phase transitions in the Blume-Emery-Griffiths (BEG) model and antiferromagnetic Potts model on the diamond lattice are investigated using the cluster-variation method in the pair approximation. The ferrimagnetic phases are found to be different from those on the simple-cubic lattice. The phase diagrams of the BEG model are also calculated. In the vicinity of the parameter line where the BEG model reduces to the three-state antiferromagnetic Potts model, new types of phase diagram are obtained. The results are different from those of the mean-field theory, which is a good approximation only for large coordination number of the lattice. 相似文献
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An exact solution of the Naive Schwinger model on lattice is found.The continuous limit of the solution is discussed.The result is that the Naive lattice gauge theory can not cut off the unphysical states of the Schwinger model in the high-energy limit. 相似文献