Swiss Light Source, Paul Scherrer Institute, CH-5232 Villigen PSI, Switzerland.
Phys Rev Lett. 2012 Jun 22;108(25):257005. doi: 10.1103/PhysRevLett.108.257005. Epub 2012 Jun 19.
We present a soft x-ray angle-resolved photoemission spectroscopy (SX-ARPES) study of the stoichiometric pnictide superconductor LaRu(2)P(2). The observed electronic structure is in good agreement with density functional theory (DFT) calculations. However, it is significantly different from its counterpart in high-temperature superconducting Fe pnictides. In particular, the bandwidth renormalization present in the Fe pnictides (~2-3) is negligible in LaRu(2)P(2) even though the mass enhancement is similar in both systems. Our results suggest that the superconductivity in LaRu(2) P(2) has a different origin with respect to the iron pnictides. Finally, we demonstrate that the increased probing depth of SX-ARPES, compared to the widely used ultraviolet ARPES, is essential in determining the bulk electronic structure in the experiment.
我们呈现了对化学计量比的磷化物超导体 LaRu(2)P(2) 的软 X 射线角分辨光电子能谱 (SX-ARPES) 研究。观察到的电子结构与密度泛函理论 (DFT) 计算结果非常吻合。然而,它与高温超导 Fe 磷化物的对应物有很大的不同。特别是,在 Fe 磷化物中存在的带宽重整化 (~2-3) 在 LaRu(2)P(2) 中可以忽略不计,尽管两个系统中的质量增强相似。我们的结果表明,LaRu(2)P(2)中的超导性与铁磷化物的超导性具有不同的起源。最后,我们证明了与广泛使用的紫外光角分辨光电子能谱相比,软 X 射线角分辨光电子能谱在确定实验中的体电子结构方面具有更大的探测深度。