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arXiv 1005.2852cond-mat.str-el
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Anderson-Holstein和Holstein-哈伯德模型中局域涨落概率分布的数值重整化群研究

Numerical Renormalization Group Study of Probability Distributions for Local Fluctuations in the Anderson-Holstein and Holstein-Hubbard Models

Alex C. Hewson, Johannes Bauer

摘要:

我们表明,局部波动的概率密度的信息可以从一个数值重整化群计算的减少密度矩阵。我们将这种方法应用于Anderson-Holstein杂质模型,计算了本振子位移$x$的基态概率密度$ρ(x)$.从这个密度,我们可以推导出一个有效的本地潜在的振荡器,并比较其形式从一个半经典近似作为耦合强度的函数。利用动力学平均场论将该方法推广到无限维Holstein-哈伯德模型.我们使用这种方法来比较的概率密度的位移的本地振荡器在正常的,反铁磁和电荷有序的阶段。

英文摘要:

We show that information on the probability density of local fluctuations can be obtained from a numerical renormalisation group calculation of a reduced density matrix. We apply this approach to the Anderson-Holstein impurity model to calculate the ground state probability density $ρ(x)$ for the displacement $x$ of the local oscillator. From this density we can deduce an effective local potential for the oscillator and compare its form with that obtained from a semiclassical approximation as a function of the coupling strength. The method is extended to infinite dimensional Holstein-Hubbard model using dynamical mean field theory. We use this approach to compare the probability densities for the displacement of the local oscillator in the normal, antiferromagnetic and charge ordered phases.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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