论文标题
cecu $ _ {2} $ si $ _ {2} $和ybrh $ _ {2} $ si $ _ {2} $：奇怪的案例，奇怪的是hever-fermion超导性的案例
CeCu$_{2}$Si$_{2}$ and YbRh$_{2}$Si$_{2}$: Strange Cases of Heavy-Fermion Superconductivity
论文作者
论文摘要
重毛绒超导体CECU $ _ {2} $ si $ _ {2} $展示了两波段，$ d $ - 波超导率，在整个费米表面上有有限的能量差距，在磁性不稳定的整个Fermi表面上，抑制了4 $ f $ antyantembotivity。相比之下，在YBRH $ _ {2} $ si $ _ {2} $ heavy-fermion超导率仅当4 $ f $ -e-electRonic抗fiferromagnetic Order在超低温度下由组合的核和4 $ f $ -spin订单更换。而两种化合物都表现出不同的抗铁磁性变体，即Cecu $ _ {2} $ _ {2} $ si $ _ {2} $的旋转密度波量子关键点和“部分”中的“ partial-mott”键入ybrh $ _ {2} $ _ {2} $ si $ _ $ _ { ybrh $ _ {2} $ si $ _ {2} $中的“奇怪金属”行为似乎是由大到小的费米表面波动驱动的。这些材料的运输特性和扫描隧道光谱（STS）以下至非常低的温度为主。近野晶格的进一步开放问题包括超导性和抗铁磁序之间的相互作用以及晶格相干性的发作。虽然超导性和抗势力磁性的显微镜共存似乎需要足够大的交错矩，但运输测量和STS中晶格相干性的发作和STS的开始仅与晶体型二倍基态息息相关，而它涉及ARPES中脱发的Hund统治倍数。
The heavy-fermion superconductor CeCu$_{2}$Si$_{2}$ exhibits two-band, $d$-wave superconductivity with a finite energy gap over the whole Fermi surface around the magnetic instability where 4$f$ antiferrerromagnetic order is suppressed. In contrast, in YbRh$_{2}$Si$_{2}$ heavy-fermion superconductivity appears only when 4$f$-electronic antiferromagnetic order is replaced at ultra-low temperatures by a combined nuclear and 4$f$-spin order. Whereas both compounds exhibit different variants of antiferromagnetic instabilities, i.e., a spin-density-wave quantum critical point in CeCu$_{2}$Si$_{2}$ and one of "partial-Mott" type in YbRh$_{2}$Si$_{2}$, in both cases the Cooper pairing, as well as the pronounced "strange-metal" behavior in YbRh$_{2}$Si$_{2}$, appear to be driven by large-to-small Fermi surface fluctuations. The transport properties and scanning tunneling spectroscopy (STS) for these materials are dominated by single-ion Kondo scatterings down to very low temperatures. Further open problems of the Kondo lattice include both the interplay between superconductivity and antiferromagnetic order as well as the onset of lattice coherence. While microscopic coexistence of superconductivity and antiferromagnetism seems to require a sufficiently large staggered moment, the onset of lattice coherence in transport measurements and STS is associated solely with the crystal-field-doublet ground state, while it involves the fully degenerate Hund's rule multiplet in ARPES.
