Willers Thomas, Strigari Fabio, Hu Zhiwei, Sessi Violetta, Brookes Nicholas B, Bauer Eric D, Sarrao John L, Thompson J D, Tanaka Arata, Wirth Steffen, Tjeng Liu Hao, Severing Andrea
Institute of Physics II, University of Cologne, 50937 Cologne, Germany;
Max Planck Institute for Chemical Physics of Solids, 01187 Dresden, Germany;
Proc Natl Acad Sci U S A. 2015 Feb 24;112(8):2384-8. doi: 10.1073/pnas.1415657112. Epub 2015 Feb 9.
The interplay of structural, orbital, charge, and spin degrees of freedom is at the heart of many emergent phenomena, including superconductivity. Unraveling the underlying forces of such novel phases is a great challenge because it not only requires understanding each of these degrees of freedom, it also involves accounting for the interplay between them. Cerium-based heavy fermion compounds are an ideal playground for investigating these interdependencies, and we present evidence for a correlation between orbital anisotropy and the ground states in a representative family of materials. We have measured the 4f crystal-electric field ground-state wave functions of the strongly correlated materials CeRh1-xIrxIn5 with great accuracy using linear polarization-dependent soft X-ray absorption spectroscopy. These measurements show that these wave functions correlate with the ground-state properties of the substitution series, which covers long-range antiferromagnetic order, unconventional superconductivity, and coexistence of these two states.
结构、轨道、电荷和自旋自由度之间的相互作用是包括超导性在内的许多涌现现象的核心。揭示这些新奇物相背后的作用力是一项巨大挑战，因为这不仅需要理解这些自由度中的每一个，还涉及考虑它们之间的相互作用。基于铈的重费米子化合物是研究这些相互依存关系的理想平台，我们展示了在一类代表性材料中轨道各向异性与基态之间存在关联的证据。我们使用线性偏振相关软X射线吸收光谱法，高精度地测量了强关联材料CeRh1-xIrxIn5的4f晶体电场基态波函数。这些测量结果表明，这些波函数与替代系列的基态性质相关，该替代系列涵盖了长程反铁磁序、非常规超导性以及这两种状态的共存。
