In-plane electronic anisotropy of differently doped AFe2As2 (A = Ba, Eu) superconductors

不同掺杂的 AFe2As2 (A = Ba, Eu) 超导体的面内电子各向异性

• 批准号: 167646007
• 负责人: Professor Dr. Philipp Gegenwart
• 金额: --
• 依托单位: Lehrstuhl für Experimentalphysik VI
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2010
• 资助国家: 德国
• 起止时间: 2009-12-31 至 2017-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/167646007?language=en
• 关键词: plane; electronic; anisotropy; differently; doped

Single crystals of AFe2As2 (A=Ca, Ba, Eu) based materials and related transition metal pnictides will be synthesized, in which the strength of electronic correlations and the ground state is tuned. Specifically, we compare the effects of hole doping in Eu1-x KxFe2As2 with hydrostatic as well as chemical pressure in EuFe2(As1-xPx)2 with particular emphasis on the magnetic quantum phase transition, the emergence of superconductivity and its interplay with Eu2+ local moments. In hydrostatically or chemically pressurized EuFe2As2, the ordering of Eu-moments below 20 K leads to distinct anomalies in the superconducting properties. Additionally, in order to classify the strength of electronic correlations of iron-arsenites with respect to the cuprates and other unconventional superconductors, negative chemical pressure is applied in (Ca,Ba)Fe2(As1-xSbx)2 to tune the system towards the stronger correlated state. Furthermore, the isostructural small-bandgap insulator and antiferromagnet BaMn2As2 is tuned towards the metallic state by hole doping. Our single crystals are investigated by transport, magnetic and thermodynamic probes, as well as within collaborations by optical- and far-infrared spectroscopy, angular-resolved photo-emission spectroscopy, electron-spin resonance and further techniques.

合成了AFe_2As_2（A=Ca，Ba，Eu）基材料及相关过渡金属磷属元素化合物的单晶体，并对其电子关联和基态强度进行了调控。具体来说，我们比较了Eu 1-x KxFe 2As 2中空穴掺杂的影响与EuFe 2（As 1-xPx）2中的流体静压和化学压，特别强调磁量子相变、超导电性的出现及其与Eu的相互作用2+局部时刻。在流体静力学或化学加压EuFe 2As 2中，低于20 K的Eu矩的排序导致超导性质的明显异常。此外，为了对铁-亚砷酸盐相对于铜酸盐和其他非常规超导体的电子相关性的强度进行分类，在（Ca，Ba）Fe 2（As 1-xSbx）2中施加负化学压力以将系统调谐到更强的相关状态。此外，同构的小带隙绝缘体和反铁磁体BaMn 2As 2被调谐向金属状态的空穴掺杂。我们的单晶通过传输，磁性和热力学探针进行研究，以及通过光学和远红外光谱，角分辨光发射光谱，电子自旋共振和其他技术进行合作。

项目成果

Experimental evidence for importance of Hund's exchange interaction for incoherence of charge carriers in iron-based superconductors

洪德交换相互作用对铁基超导体中载流子不相干性重要性的实验证据

• DOI: 10.1103/physrevb.95.144513
• 发表时间: 2017
• 期刊: Physical Review B
• 影响因子: 3.7
• 作者: J. Fink;E.D.L. Rienks;S. Thirupathaiah;J. Nayak;A. van Roekeghem;S. Biermann;T. Wolf;P. Adelmann;H.S. Jeevan;P. Gegenwart;S. Wurmehl;C. Felser;B. Büchner
• 通讯作者: B. Büchner

Linkage between scattering rates and superconductivity in doped ferropnictides

• DOI: 10.1103/physrevb.103.155119
• 发表时间: 2021-04-12
• 期刊: PHYSICAL REVIEW B
• 影响因子: 3.7
• 作者: Fink, J.;Rienks, E. D. L.;Buechner, B.
• 通讯作者: Buechner, B.

Microscopic Theory of Magnetic Detwinning in Iron-Based Superconductors with Large-Spin Rare Earths

大自旋稀土铁基超导体磁解孪微观理论

• DOI: 10.1103/physrevx.8.011011
• 发表时间: 2018
• 期刊: Physical Review X
• 影响因子: 12.5
• 作者: Jannis Maiwald;I.I. Mazin;Philipp Gegenwart
• 通讯作者: Philipp Gegenwart