论文标题
单向电荷密度波的光谱证据$ _2 $
Spectral Evidence for Unidirectional Charge Density Wave in Detwinned BaNi$_2$As$_2$
论文作者
论文摘要
在基于铁的超导体的情况下，与交织的电子订单接近的非常规超导的出现尤其重要。该顺序由这些系统中的电子列顺序和旋转密度波组成。 Bani $ _2 $ AS $ _2 $，就像其著名的基于铁的模拟Bafe $ _2 $ AS $ _2 $一样，还举办了一种破坏对称性的结构过渡，该过渡与单向电荷密度密度波（CDW）耦合，提供了一个新的平台来研究交织的订单。在这里，通过系统的角度分辨光发光光谱研究，结合了$ b_1g $单轴菌株，我们确定了由于结构过渡以及CDW诱导的带折叠而引起的带演变的不同光谱证据。与Bafe $ _2 $中的nematicition和旋转密度波相反，观察到Bani $ _2 $中的结构和CDW订单参数是$ _2 $的，是强烈耦合的，并且在单轴菌株的存在下不会分开。我们的测量结果指出，Bani $ _2 $ as $ _2 $的CDW的可能晶格起源。
The emergence of unconventional superconductivity in proximity to intertwined electronic orders is especially relevant in the case of iron-based superconductors. Such order consists of an electronic nematic order and a spin density wave in these systems. BaNi$_2$As$_2$, like its well-known iron-based analog BaFe$_2$As$_2$, also hosts a symmetry-breaking structural transition that is coupled to a unidirectional charge density wave (CDW), providing a novel platform to study intertwined orders. Here, through a systematic angle-resolved photoemission spectroscopy study combined with a detwinning $B_1g$ uniaxial strain, we identify distinct spectral evidence of band evolution due to the structural transition as well as CDW-induced band folding. In contrast to the nematicity and spin density wave in BaFe$_2$As$_2$, the structural and CDW order parameters in BaNi$_2$As$_2$ are observed to be strongly coupled and do not separate in the presence of uniaxial strain. Our measurements point to a likely lattice origin of the CDW in BaNi$_2$As$_2$.
