Divergence of the quadrupole-strain susceptibility of the electronic nematic system YbRu2Ge2
Divergence of the quadrupole-strain susceptibility of the electronic nematic system YbRu2Ge2
复制标题
电子向列系YbRu2Ge2四极应变磁化率的散度
DOI：
10.1073/pnas.1818910116
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发表时间：
2019
影响因子：
11.1
通讯作者：
I. Fisher
中科院分区：
文献类型：
--
作者：
E. Rosenberg;J. Chu;J. Ruff;A. Hristov;I. Fisher
许多强关联的量子材料，包括一些高温超导体，都表现出“电子对称”相，即电子性质自发地破坏了晶体的旋转对称性。然而，在这些复杂的系统中，相应的涨落所起的作用还不清楚，这促使人们寻找更简单的模型系统。在这里，我们确定了一个特定的4f金属间化合物材料，表现出铁四极顺序，YbRu2Ge2，只是这样一个模型系统。我们还提供了一个强大的和准确的方法来探测一个重要的相关量，四极应变磁化率的分歧。这个量的温度依赖性提供了洞察的相互作用，导致铁四极顺序，在这种情况下，磁弹性耦合的性质。与稀土离子局域4f原子轨道相关的铁四极矩序是电子四极矩序的一种实现。然而，有相对较少的金属间化合物材料的例子，表现出连续的铁四极相变，激发了对属于这一类别的其他材料的搜索。此外，还不清楚基于输运测量的实验方法是否在4f金属间化合物材料的情况下同样有效，所述实验方法已经成功地用于探测诸如Fe基超导体的材料中的磁化率。其中重要的电子自由度是局部的而不是巡回的，因此与电荷的耦合较弱，携带着接近费米能量的准粒子在目前的工作中，我们表明，金属间化合物YbRu2Ge2表现出四方相到正交相的转变符合铁四极顺序的Yb离子，并继续表明，弹性电阻率测量确实可以提供一个清晰的窗口，在这个系统中的发散磁化率。这种材料提供了一个竞技场，在其中研究的原因和后果的电子nematicity。
Significance A wide range of strongly correlated quantum materials, including some high-temperature superconductors, exhibit “electronic nematic” phases, in which the electronic properties spontaneously break the rotational symmetry of the crystal. However, the role that the corresponding nematic fluctuations play in these complicated systems is unclear, motivating the search for simpler model systems. Here, we identify a particular 4f intermetallic material which exhibits ferroquadrupole order, YbRu2Ge2, as just such a model system. We also provide a robust and accurate method to probe the divergence of an important associated quantity, the quadrupole-strain susceptibility. The temperature dependence of this quantity provides insight into the nature of the interactions that lead to ferroquadrupole order, in this case, magnetoelastic coupling. Ferroquadrupole order associated with local 4f atomic orbitals of rare-earth ions is a realization of electronic nematic order. However, there are relatively few examples of intermetallic materials which exhibit continuous ferroquadrupole phase transitions, motivating the search for additional materials that fall into this category. Furthermore, it is not clear a priori whether experimental approaches based on transport measurements which have been successfully used to probe the nematic susceptibility in materials such as the Fe-based superconductors will be as effective in the case of 4f intermetallic materials, for which the important electronic degrees of freedom are local rather than itinerant and are consequently less strongly coupled to the charge-carrying quasiparticles near the Fermi energy. In the present work, we demonstrate that the intermetallic compound YbRu2Ge2 exhibits a tetragonal-to-orthorhombic phase transition consistent with ferroquadrupole order of the Yb ions and go on to show that elastoresistivity measurements can indeed provide a clear window on the diverging nematic susceptibility in this system. This material provides an arena in which to study the causes and consequences of electronic nematicity.
影响因子：
19.6
作者：
Kretzschmar, F.;Boehm, T.;Hackl, R.
通讯作者：
Hackl, R.