ARPES view on surface and bulk hybridization phenomena in the antiferromagnetic Kondo lattice CeRh2Si2.
ARPES view on surface and bulk hybridization phenomena in the antiferromagnetic Kondo lattice CeRh2Si2.
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DOI：
10.1038/ncomms11029
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发表时间：
2016-03-18
影响因子：
16.6
通讯作者：
Vyalikh DV
中科院分区：
文献类型：
--
作者：
Patil S;Generalov A;Güttler M;Kushwaha P;Chikina A;Kummer K;Rödel TC;Santander-Syro AF;Caroca-Canales N;Geibel C;Danzenbächer S;Kucherenko Y;Laubschat C;Allen JW;Vyalikh DV
稀土材料中局域 4f 电子和流动电子之间的杂化产生了它们的奇特特性，如价态涨落、近藤行为、重费米子或非常规超导性。在这里，我们提出了近藤晶格反铁磁体 CeRh2Si2 的角分辨光电子能谱 (ARPES) 研究，其中表面和块体 Ce-4f 光谱响应得到了清晰的解析。由于更大的 f-d 杂化，在从 Si 终端晶体获取的体 Ce-4f 光谱中，Ce 终端表面看到的明显 4f 0 峰受到强烈抑制。最有趣的是，块体 Ce-4f 光谱揭示了费米边附近的精细结构，反映了块体磁性 4f 15/2 态的晶体电场分裂。这种结构在跨越价态时呈现出清晰的色散，提供了 f-d 杂化的直接证据。我们的研究结果提供了对 f-d 杂化现象的精确洞察，并强调了它们在近藤晶格反铁磁相中的重要性。 在稀土金属间化合物中，局域 4f 电子和流动电子之间的相互作用会导致奇异的物质状态。在这里，作者使用光电子能谱来揭示和研究近藤晶格反铁磁体 CeRh2Si2 本体和表面的这种相互作用。
The hybridization between localized 4f electrons and itinerant electrons in rare-earth-based materials gives rise to their exotic properties like valence fluctuations, Kondo behaviour, heavy-fermions, or unconventional superconductivity. Here we present an angle-resolved photoemission spectroscopy (ARPES) study of the Kondo lattice antiferromagnet CeRh2Si2, where the surface and bulk Ce-4f spectral responses were clearly resolved. The pronounced 4f 0 peak seen for the Ce terminated surface gets strongly suppressed in the bulk Ce-4f spectra taken from a Si-terminated crystal due to much larger f-d hybridization. Most interestingly, the bulk Ce-4f spectra reveal a fine structure near the Fermi edge reflecting the crystal electric field splitting of the bulk magnetic 4f 15/2 state. This structure presents a clear dispersion upon crossing valence states, providing direct evidence of f-d hybridization. Our findings give precise insight into f-d hybridization penomena and highlight their importance in the antiferromagnetic phases of Kondo lattices. In rare-earth intermetallics, interaction between localized 4f electrons and itinerant electrons can result in exotic states of matter. Here, the authors use photoemission spectroscopy to reveal and study this interaction in the bulk and at the surface of the Kondo lattice antiferromagnet CeRh2Si2.