论文标题
抗铁磁性Delafossite pdcro $ _2 $中的扭曲双层手性旋转结构
Twisted double-layer chiral spin structures in anti-ferromagnetic delafossite PdCrO$_2$
论文作者
论文摘要
我们预测，Delafossite PDCRO $ _2 $的抗铁磁（AFM）磁性结构具有交错的手性，沿着$ z $轴的双层周期性具有有趣的磁各向异性。我们通过进行密度功能理论（DFT）计算来研究PDCRO $ _2 $的电子和磁性结构。原定的基础状态证明了带有交错性手性的120美元$^\ Circ $ afm订购。结果与以前的中子实验一致，但是我们的计算决定了高对称易于平面和局部轴心结构的更详细信息。我们研究了交错的手性的起源以及易于平面和局部轴心的方向。基于DFT和有效的旋转相互作用模型，我们证明了复杂的磁性排序需要新颖的四旋链相互作用，而通常通过通常的交换相互作用来描述。此外，我们显示了费米水平附近的PD电子带构成了微小的脱糖性破裂，这是由带有不同易于平面和局部孔隙轴的磁各向异性引起的。我们预计，磁性双层中的易于范围的扭曲和旋转模式可能是了解PDCRO $ _2 $的隐藏磁性及其相关的宏观属性的关键因素，如先前报道的异常大厅效应。
We predict that the anti-ferromagnetic (AFM) magnetic structure of delafossite PdCrO$_2$ has a staggered chirality with the double-layer periodicity along the $z$-axis with intriguing magnetic anisotropy. We study the electronic and magnetic structures of PdCrO$_2$ by carrying out density functional theory (DFT) calculation. The calculated ground state turns out to exhibit a 120$^\circ$ AFM ordering with staggered chirality. The result is consistent with the previous neutron experiments, but our calculations determine and provide more detailed information on the high symmetric easy-plane and local-easy-axis structure. We investigate the origin of staggered chirality as well as the easy-plane and local-easy-axis directions. Based on the DFT and effective spin interaction models, we demonstrate the complex magnetic ordering requires novel four-spin interactions, which cannot be described by the usual exchange interaction. Also, we show Pd electronic bands near the Fermi level pose a tiny degeneracy breaking, which arises from the magnetic anisotropy with different easy-plane and local-easy-axis. We expect that the twisting and rotating modes of easy-planes in the magnetic double layers can be the critical factor to understand a hidden magnetic property of PdCrO$_2$ and its related macroscopic property like the previously reported anomalous Hall effect.
