当前位置: X-MOL 学术npj Quant. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Unexpected differences between surface and bulk spectroscopic and implied Kondo properties of heavy fermion CeRh 2 Si 2
npj Quantum Materials ( IF 5.7 ) Pub Date : 2020-10-06 , DOI: 10.1038/s41535-020-00273-7
Georg Poelchen , Susanne Schulz , Max Mende , Monika Güttler , Alexander Generalov , Alexander V. Fedorov , Nubia Caroca-Canales , Christoph Geibel , Kristin Kliemt , Cornelius Krellner , Steffen Danzenbächer , Dmitry Yu. Usachov , Pavel Dudin , Victor N. Antonov , James W. Allen , Clemens Laubschat , Kurt Kummer , Yuri Kucherenko , Denis V. Vyalikh

Ultra-violet angle-resolved photoemission spectroscopy (UV-ARPES) was used to explore the temperature dependence of the Ce-4f spectral responses for surface and bulk in the antiferromagnetic Kondo lattice CeRh2Si2. Spectra were taken from Ce- and Si-terminated surfaces in a wide temperature range, and reveal characteristic 4f patterns for weakly (surface) and strongly (bulk) hybridized Ce, respectively. The temperature dependence of the Fermi level peak differs strongly for both cases implying that the effective Kondo temperature at the surface and bulk can be rather distinct. The greatly reduced crystal–electric-field (CEF) splitting at the surface gives reason to believe that the surface may exhibit a larger effective Kondo temperature because of a higher local-moment effective degeneracy. Further, the hybridization processes could strongly affect the 4f peak intensity at the Fermi level. We derived the k-resolved dispersion of the Kondo peak which is also found to be distinct due to different sets of itinerant bands to which the 4f states of surface and bulk Ce are coupled. Overall our study brings into reach the ultimate goal of quantitatively testing many-body theories that link spectroscopy and transport properties, for both the bulk and the surface, separately. It also allows for a direct insight into the broader problem of Kondo lattices with two different local-moment sublattices, providing some understanding of why the cross-talking between the two Kondo effects is weak.



中文翻译:

重铁离子CeRh 2 Si 2的表面和本体光谱与隐含的近藤性质之间的意外差异

紫外角分辨光电子能谱学(UV-ARPES)来探索CE-4的温度依赖性˚F在反铁磁近藤晶格CeRh用于表面和本体光谱响应2的Si 2。光谱是在较宽的温度范围内从Ce和Si端接的表面获取的,并显示了特征4 f弱(表面)和强(本体)杂交铈的模式。在这两种情况下,费米能级峰值的温度依赖性都存在很大差异,这表明表面和主体的有效近藤温度可能非常不同。表面上大大减小的晶体电场(CEF)分裂使我们有理由相信,由于较高的局部矩有效简并性,表面可能显示出较大的有效近藤温度。此外,杂交过程可能强烈影响费米能级的4 f峰强度。我们推导了Kondo峰的k解析色散,由于4 f表面和块体Ce的状态是耦合的。总的来说,我们的研究达到了定量测试将光谱学和传输特性联系在一起的多体理论的最终目标,这些理论分别针对体积和表面。它还可以直接了解具有两个不同局部矩子格的近藤晶格的更广泛问题,从而可以理解为什么两个近藤效应之间的串扰较弱。

更新日期:2020-10-06
down
wechat
bug