Extended one-dimensional Hubbard model: A small-cluster approach.
Extended one-dimensional Hubbard model: A small-cluster approach.
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扩展一维哈伯德模型：一种小簇方法。
DOI：
10.1103/physrevb.37.6073
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Falicov
中科院分区：
文献类型：
--
作者：
del Bosch LM;Falicov
通过小晶体方法重新检查具有最近邻跳跃、第一和第二最近邻粒子相互作用、每个位点一个粒子的一维哈伯德模型：具有周期性边界条件的四位点簇的精确解。发现对称线交叉以及奇异线和点。相关函数的分析表明，尽管当参数接近电荷到自旋密度波跃迁的值（表明初期的二阶跃迁）时存在平滑、强烈的变化，但实际的变化涉及不相关对称性之间的交叉（清楚地表明一阶跃迁）。相对简单的计算及其结果与先前的蒙特卡罗数值模拟非常吻合，并解决了密度波跃迁的阶数这一尚未解决的问题。
The one-dimensional Hubbard model with nearest-neighbor hopping, first- and second-nearest-neighbor particle interactions, and one particle per site is reexamined by means of a small-crystal approach: an exact solution of a four-site cluster with periodic boundary conditions. Lines of symmetry crossing as well as singular lines and points are found. Analysis of correlation functions indicates that although there are smooth, strong changes as the parameters approach the values of the charge-to-spin-density-wave transition (a suggestion of an incipient second-order transition), the actual change involves a crossover between unrelated symmetries (a clear indication of a first-order transition). The relatively simple calculation and its results agree well with previous Monte Carlo numerical simulations and settles the unresolved question of the order of the density-wave transition.