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arXiv 0802.1828cond-mat.str-el
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扩展Falicov-Kimball模型中电子(反)铁电性的弱耦合处理

Weak-coupling Treatment of Electronic (Anti-)Ferroelectricity in the Extended Falicov-Kimball Model

Claudia Schneider, Gerd Czycholl

摘要:

本文研究了无限维局域(f-)电子有限带宽(跳跃$t_f$)扩展的(无自旋)Falicov-Kimball模型,在半填充的小局域带间库仑关联$U$的弱耦合极限下.在导电带和f带重叠的情况下,可能存在不同类型的有序解,即电荷密度波(CDW)序、电子铁电性(EFE)和电子反铁电性(EAFE)。计算作为模型参数和温度的函数的序参量。存在从CDW相到EFE相或EAFE相的一级相变。计算总能量以确定热力学稳定的溶液。计算了量子相图。

英文摘要:

We study the (spinless) Falicov-Kimball model extended by a finite band width (hopping $t_f$) of the localized (f-) electrons in infinite dimensions in the weak-coupling limit of a small local interband Coulomb correlation $U$ for half filling. In the case of overlapping conduction- and f-bands different kinds of ordered solutions are possible, namely charge-density wave (CDW) order, electronic ferroelectricity (EFE) and electronic antiferroelectricity (EAFE). The order parameters are calculated as a function of the model parameters and of the temperature. There is a first-order phase transition from the CDW-phase to the EFE- or EAFE-phase. The total energy is calculated to determine the thermodynamically stable solution. The quantum phase diagrams are calculated.

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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