Institut für Festkörper- und Materialphysik, Technische Universität Dresden, D-01062, Dresden, Germany.
MAX IV Laboratory, Lund University, Box 118, 22100, Lund, Sweden.
Nat Commun. 2019 Feb 15;10(1):796. doi: 10.1038/s41467-019-08688-y.
Application of the Luttinger theorem to the Kondo lattice YbRhSi suggests that its large 4f-derived Fermi surface (FS) in the paramagnetic (PM) regime should be similar in shape and volume to that of the divalent local-moment antiferromagnet (AFM) EuRhSi in its PM regime. Here we show by angle-resolved photoemission spectroscopy that paramagnetic EuRhSi has a large FS essentially similar to the one seen in YbRhSi down to 1 K. In EuRhSi the onset of AFM order below 24.5 K induces an extensive fragmentation of the FS due to Brillouin zone folding, intersection and resulting hybridization of the Fermi-surface sheets. Our results on EuRhSi indicate that the formation of the AFM state in YbRhSi is very likely also connected with similar changes in the FS, which have to be taken into account in the controversial analysis and discussion of anomalies observed at the quantum critical point in this system.
吕特廷格定理在 Kondo 晶格 YbRhSi 中的应用表明，在顺磁（PM）态下，其大的 4f 衍生费米面（FS）的形状和体积应该与二价局域磁矩反铁磁体（AFM）EuRhSi 在其 PM 态下的相似。在这里，我们通过角分辨光发射谱（ARPES）表明，在 1 K 以下，顺磁 EuRhSi 具有与在 YbRhSi 中看到的基本相似的大 FS。在 EuRhSi 中，低于 24.5 K 的 AFM 序的出现由于布里渊区折叠、交叠和费米面片的杂交导致 FS 的广泛碎裂。我们在 EuRhSi 上的结果表明，YbRhSi 中 AFM 态的形成很可能也与 FS 中的类似变化有关，在对该系统中量子临界点观察到的异常进行有争议的分析和讨论时，必须考虑到这些变化。
