Specific Heat-Coefficient of YbAl3 Studied by Combined Nearly Free Electron Conduction Band Hybridized with Localized f Electrons with Correlation Effect
Specific Heat-Coefficient of YbAl3 Studied by Combined Nearly Free Electron Conduction Band Hybridized with Localized f Electrons with Correlation Effect
复制标题
具有相关效应的局域f电子杂化的近自由电子导带组合研究YbAl3的比热系数
DOI：
10.1143/jpsj.78.064707
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发表时间：
2009
影响因子：
1.7
通讯作者：
T. Saso
中科院分区：
文献类型：
--
作者：
Yoshiki Imai;T. Saso
基于最近提出的能带模型，研究了中重电子化合物YbAl3的电子比热。哈密顿量的带项由三部分组成：用近自由电子方法描述的传导电子、Yb离子的定域4f电子以及这些电子之间的杂化项。提取费米能级附近的几个能带，重建低能有效哈密顿量，以考虑关联效应，并用自洽二阶微扰理论结合局域近似进行了研究。根据内能的数值导数，计算出比热cv(T)与温度T的函数关系。索末菲系数γ也是由直接公式计算出来的。Cv(T)/T的总体结构与实验结果定量一致，具有典型的双峰结构。它们起源于关联效应。
Based on the recently proposed band model, the electronic specific heat of moderately heavy electron compound YbAl 3 are investigated. The band term of the Hamiltonian consists of three parts; conduction electrons described by the nearly free electron method, localized 4f electrons of Yb ions and the hybridization term between these electrons. Extracting several bands near the Fermi level, we reconstruct the low-energy effective Hamiltonian in order to consider the correlation effect, which is studied by using the self-consistent second order perturbation theory combined with local approximation. The temperature dependence of the specific heat c v ( T ) is calculated as a function of temperature T from the numerical derivative of the internal energy. Sommerfeld coefficient γ is also calculated from the direct formula. The overall structure of c v ( T )/ T is in quantitative agreement with the experimental results, which have the characteristic two-peak structures. They originate from the correlation effec...