铁硫系超导体中轨道选择性与Pomeranchuk不稳定性的关系：双圈重整化群研究
Orbital selectivity versus Pomeranchuk instability in the iron-chalcogenide superconductors: A two-loop renormalization group study
摘要：
我们对一个二维有效多带模型进行了双圈重整化群（RG）分析，该模型与描述某些铁硫系超导材料的低能性质有关。在这个分析中的关键成分是计算高阶贡献的RG计划，超越了广泛使用的镶木地板近似和随之而来的列入非平凡的自能效应的模型，产生各向异性重整化的准粒子的重量在系统中。我们工作的动机是Sprau等人（2017）的实验发现，在中等温度下Hund金属相中准粒子重量的轨道选择性重正化支持了FeSe化合物在较低温度下超导相中极不寻常的间隙。我们在这里得到的一个预测是，在这些系统中的向列性的潜在起源可能确实来自轨道选择性，而不是在$d_{\pm}$通道的Pomeranchuk不稳定性。这种轨道选择性是由模型中存在的条纹型反铁磁波动驱动的。因此，我们认为，目前的RG结果可能提供一个方案，从弱到中等耦合的角度来看，其中的轨道选择性的作用，以描述一些铁硫系超导体的物理性质被强调。
英文摘要：
We perform a two-loop renormalization group (RG) analysis of a 2D effective multiband model, which is relevant for describing the low-energy properties of some iron-chalcogenide superconducting materials. Crucial ingredients in this analysis are the calculation of higher-order contributions in the RG scheme that go beyond the widely-used parquet approximation and the consequent inclusion of nontrivial self-energy effects of the model that yield an anisotropic renormalization of the quasiparticle weight in the system. The motivation of our work is the experimental discovery by Sprau et al. (2017) that orbitally-selective renormalization of the quasiparticle weight in the Hund's metal phase at moderate temperatures underpins the highly unusual gap in the superconducting phase of the FeSe compound at lower temperatures. One prediction we arrive here is that the underlying origin of nematicity in these systems may indeed come from orbital-selectivity, instead of a Pomeranchuk instability in the $d_{\pm}$ channel. This orbital selectivity is driven by the presence of stripe-type antiferromagnetic fluctuations in the model. Therefore, we argue that the present RG results may provide a scenario from a weak-to-moderate coupling perspective, in which the role of orbital selectivity to describe the physical properties of some iron-chalcogenide superconductors is emphasized.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
