用角分辨光电子能谱研究了NaFe $_{1-x}$ Co $_x$ As从最佳掺杂超导化合物（$x=0.028$）到重过掺杂非超导化合物（$x=0.109$）的电子结构。与“122”型铁磷属元素化合物的情况类似，我们的数据表明，在NaFe $_{1-x}$ Co $_x$ As中的Co掺杂提供了额外的载流子，并相应地移动了费米能级。在$x=0.109$化合物中，围绕带中心$Γ$的空穴状带移动到更深的结合能，而出现电子口袋。在整个掺杂范围内，我们研究的整体能带重整化基本上保持不变，这表明局部磁/电子相关性不受载流子掺杂的影响。我们推测，流动载流子的巡游特性和局域相互作用之间的平衡可能对超导性起着重要的作用。
英文摘要：
Using angle-resolved photoemission spectroscopy, we studied the electronic structure of NaFe$_{1-x}$Co$_x$As from an optimally doped superconducting compound ($x=0.028$) to a heavily overdoped non-superconducting one ($x=0.109$). Similar to the case of "122" type iron pnictides, our data suggest that Co dopant in NaFe$_{1-x}$Co$_x$As supplies extra charge carriers and shifts the Fermi level accordingly. In the $x=0.109$ compound, the hole-like bands around the zone center $Γ$ move to deeper binding energies and an electron pocket appears instead. The overall band renormalization remains basically the same throughout the doping range we studied, suggesting that the local magnetic/electronic correlations are not affected by carrier doping. We speculate that a balance between itinerant properties of mobile carriers and local interactions may play an important role for the superconductivity.
Incommensurate Antiferromagnetic Order in the Fe-substituted Bi-2201 Cuprate in the Heavily Overdoped Regime
Sophia University（上智大学）；RIKEN Nishina Center（理化学研究所仁科中心）；Institute for Materials Research, Tohoku University（东北大学材料科学研究所）；ISIS Pulsed Neutron and Muon Source, STFC Rutherford Appleton Laboratory（STFC卢瑟福阿普顿实验室ISIS脉冲中子与μ子源）；Neutron Scattering Division, Oak Ridge National Laboratory（橡树岭国家实验室中子散射部）；Institute for Solid State Physics, The University of Tokyo（东京大学固体物理研究所）；Department of Natural Sciences, Tokyo Denki University（东京电机大学自然科学系）
Phase diagram and physical properties of NaFe$_{1-x}$Cu$_x$As single crystals
采用自熔法生长了一系列高质量的NaFe $_{1-x}$ Cu $_x$ As单晶，并通过结构、输运、热力学和高压测试对其进行了系统的表征。Cu掺杂抑制了结构和磁性转变，并诱导了体超导电性。超导转变温度（$T_c$）最初提高从9.6到11.5 K的Cu掺杂，然后抑制进一步掺杂。获得了类似于NaFe $_{1-x}$ Co $_x$ As的相图，除了在极度过掺杂的样品中观察到绝缘而不是金属行为。欠掺杂、最佳掺杂和过掺杂样品的$T_c$均通过施加压力而显著增强。虽然在欠掺杂和最佳掺杂的NaFe $_{1-x}$ Co $_x$ As中观察到约31 K的在外部压力下的通用最大转变温度（$T_c^{max}$），但NaFe $_{1-x}$ Cu $_x$ As的$T_c^{max}$被Cu掺杂单调抑制，表明在NaFeAs中Cu的杂质势比Co强。比较了Cu和Co在NaFeAs中的掺杂效应，结果表明，Cu是一种有效的电子掺杂剂，具有很强的杂质势，但部分掺杂电子是局域化的，并没有像刚性能带模型所预测的那样填满能带。
Cu Nuclear Quadrupole Resonance Study of La_{2-x}Sr_xCu_{1-y}Zn_yO_4 (x=0.10, 0.15 and 0.20): Zn-induced Wipeout Effect near the Magnetic and Electric Instability
Effects of Zn and Ni substitution on the Cu-spin dynamics and superconductivity in La_2-x_Sr_x_Cu_1-y_(Zn,Ni)_y_O_4_ with x=0.15-0.20 studied by the muon spin relaxation and magnetic susceptibility
Strongly suppressed superconducting proximity effect and ferromagnetism in trilayers of $\rm Bi_2Se_3$ / $\rm SrRuO_3$ / underdoped $\rm YBa_2Cu_3O_x$: A possible new platform for Majorana nano-electronics
