论文标题
Infinite-Layer la $ _ {1-x} $ sr $ _ {x} $ nio $ _ {2} $和隐藏的hund物理学的光学特性
Optical properties of the infinite-layer La$_{1-x}$Sr$_{x}$NiO$_{2}$ and hidden Hund's physics
论文作者
论文摘要
我们使用DFT+DMFT调查了Infinite-Layer la $ _ {1-X} $ sr $ _x $ nio $ _2 $的普通状态的光学性质。我们发现一种相关金属，该金属表现出相对于密度功能理论的高能量向高能量的大量转移。相关性不是由于Mott物理学引起的，这会抑制电荷波动和综合光谱重量，因为我们接近推定的绝缘状态。取而代之的是，我们发现不寻常的情况是，随着掺杂和{\的增加，集成的光谱重量{\它会随着温度的升高而减小}。我们将其与光导率的连贯成分进行对比，该组件由于连贯$ - $ - $不连贯的交叉而随温度的增加而{\降低}。我们的光学研究支持了hund的金属状态的图片，即使在低能量下，费米表面主要具有$ d_ {x^2-y^2} $字符，在中间能量下，动态轨道波动也可以看到，我们提出了一个低富集的两种频率模型，该模型具有Atom中心$ e_g $ e_g $的状态。
We investigate the optical properties of the normal state of the infinite-layer La$_{1-x}$Sr$_x$NiO$_2$ using DFT+DMFT. We find a correlated metal which exhibits substantial transfer of spectral weight to high energies relative to the density functional theory. The correlations are not due to Mott physics, which would suppress the charge fluctuations and integrated optical spectral weight as we approach a putative insulating state. Instead we find the unusual situation, that the integrated optical spectral weight {\it decreases} with doping and {\it increases } with increasing temperature. We contrast this with the coherent component of the optical conductivity, which {\it decreases} with increasing temperature as a result of a coherence$-$incoherence crossover. Our optical studies support a picture of a Hund's metallic state, where dynamical orbital fluctuations are visible at intermediate energies, even if at low energies the Fermi surface has primarily $d_{x^2 - y^2}$ character and we propose a low-energy two-band model with atom centered $e_g$ states.
