Division of Materials Science and Engineering, The Ames Laboratory, U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, USA.
Phys Rev Lett. 2011 Dec 23;107(26):267002. doi: 10.1103/PhysRevLett.107.267002.
We use high resolution angle-resolved photoemission to study the electronic structure of the iron based high-temperature superconductors Ba(Fe(1-x)Ru(x))(2)As(2) as a function of Ru concentration. We find that substitution of Ru for Fe is isoelectronic, i.e., it does not change the value of the chemical potential. More interestingly, there are no measured, significant changes in the shape of the Fermi surface or in the Fermi velocity over a wide range of substitution levels (0<x<0.55). Given that the suppression of the antiferromagnetic and structural phase is associated with the emergence of the superconducting state, Ru substitution must achieve this via a mechanism that does not involve changes of the Fermi surface. We speculate that this mechanism relies on magnetic dilution which leads to the reduction of the effective Stoner enhancement.
我们利用高分辨率角分辨光电子能谱研究了铁基高温超导体 Ba(Fe(1-x)Ru(x))(2)As(2) 的电子结构随 Ru 浓度的变化。我们发现 Ru 取代 Fe 是等电子的，即它不会改变化学势的值。更有趣的是，在很宽的取代水平范围内（0<x<0.55），费米面的形状或费米速度都没有明显的变化。鉴于反铁磁和结构相的抑制与超导态的出现有关，Ru 取代必须通过一种不涉及费米面变化的机制来实现。我们推测，这种机制依赖于磁稀释，从而导致有效斯通纳增强的降低。
