论文标题
Cak中的磁性及其与超导性的共存（fe $ _ {0.949} $ ni $ _ {0.051} $）$ _ 4 $ as 4 $ as $ _4 $：MUON旋转/放松研究
Magnetism and its coexistence with superconductivity in CaK(Fe$_{0.949}$Ni$_{0.051}$)$_4$As$_4$: muon spin rotation/relaxation studies
论文作者
论文摘要
CAK（Fe $ _ {0.949} $ ni $ _ {0.051} $）$ _ 4 $ AS $ _4 $的磁响应（$ ni $ _ {0.051} $）的磁响应。远程相称的磁顺序设置在Néel温度以下$ t _ {\ rm n} = 50.0（5）$ 〜k。密度功能理论的计算已经确定了三个可能的muon停止位点。发现实验数据仅与一种类型的磁性结构一致，即，在$ ab-$平面内具有刺猬基序的远程磁性旋转涡流 - 晶状体和沿$ c- $方向进行的抗铁磁堆积。在$ t \ of3 $ k上的有序磁矩的值估计为$ m _ {\ rm fe} = 0.38（11）$ $ $ $ $ $ _ {\ rm b} $（$μ__ {\ rm b} $是bohr magneton）。观察到磁性和超导阶段的显微镜共存，伴随着在超导过渡温度下方的磁顺序参数降低$ t _ {\ rm c} \ simeq 9 $ k。与11、122和1144个基于Fe的Pnictides家族的比较表明，在$ t \ rightarrow 0 $的磁顺序参数的降低与过渡温度的比率$ t _ {\ rm c}/t _ {\ rm n} $之间存在相关性。发现这种相关性是通过Machida模型描述的，用于巡回旋转密度波磁和超导性的共存[Machida，J。Phys。 Soc。 JPN。 50，2195（1981）和Bud'ko等人，物理学。 Rev. B 98，144520（2018）]。
The magnetic response of CaK(Fe$_{0.949}$Ni$_{0.051}$)$_4$As$_4$ was investigated by means of the muon-spin rotation/relaxation. The long-range commensurate magnetic order sets in below the Néel temperature $T_{\rm N}= 50.0(5)$~K. The density-functional theory calculations have identified three possible muon stopping sites. The experimental data were found to be consistent with only one type of magnetic structure, namely, the long-range magnetic spin-vortex-crystal order with the hedgehog motif within the $ab-$plane and the antiferromagnetic stacking along the $c-$direction. The value of the ordered magnetic moment at $T\approx3$ K was estimated to be $m_{\rm Fe}=0.38(11)$ $μ_{\rm B}$ ($μ_{\rm B}$ is the Bohr magneton). A microscopic coexistence of magnetic and superconducting phases accompanied by a reduction of the magnetic order parameter below the superconducting transition temperature $T_{\rm c}\simeq 9$ K is observed. Comparison with 11, 122, and 1144 families of Fe-based pnictides points to existence of correlation between the reduction of the magnetic order parameter at $T\rightarrow 0$ and the ratio of the transition temperatures $T_{\rm c}/T_{\rm N}$. Such correlations were found to be described by Machida's model for coexistence of itinerant spin-density wave magnetism and superconductivity [Machida, J. Phys. Soc. Jpn. 50, 2195 (1981) and Bud'ko et al., Phys. Rev. B 98, 144520 (2018)].
