论文标题
DFT+U和量子蒙特卡洛研究Agnio $ _2 $和Agni $ _ {1-x} $ co $ _ {x} $ o $ $ $ _2 $ delafossite的电子和光学特性研究
DFT+U and Quantum Monte Carlo study of electronic and optical properties of AgNiO$_2$ and AgNi$_{1-x}$Co$_{x}$O$_2$ delafossite
论文作者
论文摘要
作为唯一的半金属$ d^{10} $ - 基于Delafossite，Agnio $ _2 $由于其独特的半金色和nio $ _2 $层中的反铁磁性而受到了很大的关注，与lattice扭曲相结合。相反，其他Delafossites（例如Agcoo $ _2 $）正在绝缘。在这里，我们研究了Agni $ _ {1-x} $ CO $ _ {x} $ o $ _2 $合金的电子结构如何随Ni/CO浓度而变化，以研究金属金属层的电子属性和相位稳定性。虽然已经使用密度功能理论（DFT）研究了Delafossites的电子和磁性结构，但较早的研究尚未校正强烈的现场库仑相互作用。为了准确处理这些相互作用，在这项研究中，我们使用量子蒙特卡洛（QMC）模拟来获得Agnio $ _2 $的电子和磁性的准确估计。与DFT结果相比，我们表明这些电子相关性至关重要。我们表明，在磁性NI站点上的掺杂会导致金属 - 绝缘体过渡附近$ x \ sim 0.33 $，并在$ x \ sim 0.66 $附近的重入行为。
As the only semimetallic $d^{10}$-based delafossite, AgNiO$_2$ has received a great deal of attention due to both its unique semimetallicity and its antiferromagnetism in the NiO$_2$ layer that is coupled with a lattice distortion. In contrast, other delafossites such as AgCoO$_2$ are insulating. Here we study how the electronic structure of AgNi$_{1-x}$Co$_{x}$O$_2$ alloys vary with Ni/Co concentration, in order to investigate the electronic properties and phase stability of the intermetallics. While the electronic and magnetic structure of delafossites have been studied using Density Functional Theory (DFT), earlier studies have not included corrections for strong on-site Coulomb interactions. In order to treat these interactions accurately, in this study we use Quantum Monte Carlo (QMC) simulations to obtain accurate estimates for the electronic and magnetic properties of AgNiO$_2$. By comparison to DFT results we show that these electron correlations are critical to account for. We show that Co doping on the magnetic Ni sites results in a metal-insulator transition near $x\sim 0.33$, and reentrant behavior near $x\sim 0.66$
