Institut für Festkörperphysik, Technische Universität Dresden, D-01062 Dresden, Germany.
Phys Rev Lett. 2011 Dec 23;107(26):267601. doi: 10.1103/PhysRevLett.107.267601. Epub 2011 Dec 22.
Angle-resolved photoelectron spectroscopy (ARPES) was used to study the Fermi surface of the heavy-fermion system YbRh(2)Si(2) at a temperature of about 10 K, i.e., a factor of 2 below the Kondo energy scale. We observed sharp structures with a well-defined topology, which were analyzed by comparing with results of band-structure calculations based on the local-density approximation (LDA). The observed bulk Fermi surface presents strong similarities with that expected for a trivalent Yb state, but is slightly larger, has a strong Yb-4f character, and deviates from the LDA results by a larger region without states around the Γ point. These properties are qualitatively explained in the framework of a simple f-d hybridization model. Our analysis highlights the importance of taking into account surface states and doing an appropriate projection along k(z) when comparing ARPES data with results from theoretical calculations.
角分辨光电子能谱（ARPES）被用于研究在约 10 K 的温度下重费米子体系 YbRh2Si2 的费米面，即低于 Kondo 能量标度的两倍。我们观察到了具有明确定义拓扑结构的尖锐结构，通过与基于局域密度近似（LDA）的能带结构计算的结果进行比较，对这些结构进行了分析。观察到的体费米面与预期的三价 Yb 态非常相似，但稍大一些，具有强烈的 Yb-4f 特征，并且在 Γ 点附近没有状态的区域与 LDA 结果相差较大。这些性质在简单的 f-d 杂化模型框架内得到了定性解释。我们的分析强调了在将 ARPES 数据与理论计算结果进行比较时，考虑表面态并沿 k(z) 进行适当投影的重要性。
