论文标题
重费菲尔米ce的轨道各向异性
Orbital anisotropy of heavy fermion Ce$_{2}$IrIn$_{8}$ under crystalline electric field and its energy scale
论文作者
论文摘要
我们使用第一原理动态场理论结合了密度函数理论，研究了轨道各向异性的温度（$ t $） - 轨道各向异性的演变及其对CE $ _ {2} $ irin $ _ {8} $的影响的影响。轨道各向异性通过降低$ t $而发展，并且在与晶体电场（CEF）分裂尺寸相对应的温度以下加剧。有趣的是，CEF激发态的人口减少在费米水平的$ t $依赖性光谱函数中留下了光谱签名“肩膀”。从两轨道的安德森杂质模型来看，我们证明了CEF分裂大小是影响“肩膀”的出现和位置的关键成分。除了两个常规温度尺度$ t_ {k} $和$ t^{*} $之外，我们还引入了一个额外的温度尺度，以处理重型费米昂系统中的轨道各向异性。
We investigate the temperature ($T$)-evolution of orbital anisotropy and its effect on spectral function and optical conductivity in Ce$_{2}$IrIn$_{8}$, using a first principles dynamical mean field theory combined with density functional theory. The orbital anisotropy develops by lowering $T$ and it is intensified below a temperature corresponding to the crystalline-electric field (CEF) splitting size. Interestingly, the depopulation of CEF excited states leaves a spectroscopic signature, "shoulder", in the $T$-dependent spectral function at the Fermi level. From the two-orbital Anderson impurity model, we demonstrate that CEF splitting size is the key ingredient influencing the emergence and the position of the "shoulder". Besides the two conventional temperature scales $T_{K}$ and $T^{*}$, we introduce an additional temperature scale to deal with the orbital anisotropy in heavy fermion systems.
