Dallera C, Grioni M, Shukla A, Vankó G, Sarrao J L, Rueff J P, Cox D L
INFM-Dipartimento di Fisica, Politecnico di Milano, Piazza Leonardo da Vinci 32, I-20133 Milano, Italy.
Phys Rev Lett. 2002 May 13;88(19):196403. doi: 10.1103/PhysRevLett.88.196403. Epub 2002 Apr 26.
Resonant inelastic x-ray scattering (RIXS) yields clear evidence of spectroscopic Kondo scales in heavy fermions. In YbInCu4 and YbAgCu4 RIXS probes the Yb2+ component of the hybrid ground state and the temperature dependence of the Yb 4f occupation. We report a sudden valence change at a phase transition in YbInCu4, but a continuous temperature dependence in YbAgCu4, consistent with the predictions of the Anderson impurity model, for a Kondo temperature T(K) = 70 K. These results solve a long-standing controversy and establish RIXS as a quantitative probe of the electronic structure of strongly correlated electron systems.
共振非弹性X射线散射（RIXS）为重费米子中的光谱近藤标度提供了清晰的证据。在YbInCu4和YbAgCu4中，RIXS探测混合基态的Yb2+成分以及Yb 4f占据的温度依赖性。我们报道了YbInCu4在相变时的突然价态变化，但YbAgCu4中存在连续的温度依赖性，这与对于近藤温度T(K)=70 K的安德森杂质模型的预测一致。这些结果解决了一个长期存在的争议，并将RIXS确立为强关联电子系统电子结构的定量探针。
