论文标题
SR $ _2 $ ruo $ _4 $的两部分超导订单参数的热力学证据
Thermodynamic Evidence for a Two-Component Superconducting Order Parameter in Sr$_2$RuO$_4$
论文作者
论文摘要
SR $ _2 $ ruo $ _4 $已成为26年的旋转三角体超导体的领先候选人。但是，最近的NMR实验对这种候选资格表示怀疑，很难找到与所有实验一致的超导性理论。需要的是基于对称性的实验，可以排除广泛的可能超导订单参数的类别。在这里，我们使用谐振超声光谱法来测量SR $ _2 $ ruo $ _4 $的整个对称性分辨弹性张量通过超导过渡。我们在剪切弹性模量$ c_ {66} $中观察到热力学不连续性，要求超导顺序参数为两个组件。两个组件$ p $ - 波订单参数，例如$ p_x+i p_y $，自然会满足此要求。由于该订单参数似乎被最近的NMR实验所排除，因此我们建议其他两个两组订单参数，即$ \ weft \ {d_ {xz}，d_ {yz} \ right \} $或$ \} $或$ \。现在是SR $ _2 $ ruo $ _4 $的订单参数的主要候选人。
Sr$_2$RuO$_4$ has stood as the leading candidate for a spin-triplet superconductor for 26 years. Recent NMR experiments have cast doubt on this candidacy, however, and it is difficult to find a theory of superconductivity that is consistent with all experiments. What is needed are symmetry-based experiments that can rule out broad classes of possible superconducting order parameters. Here we use resonant ultrasound spectroscopy to measure the entire symmetry-resolved elastic tensor of Sr$_2$RuO$_4$ through the superconducting transition. We observe a thermodynamic discontinuity in the shear elastic modulus $c_{66}$, requiring that the superconducting order parameter is two-component. A two-component $p$-wave order parameter, such as $p_x+i p_y$, naturally satisfies this requirement. As this order parameter appears to be precluded by recent NMR experiments, we suggest that two other two-component order parameters, namely $\left\{d_{xz},d_{yz}\right\}$ or $\left\{d_{x^2-y^2},g_{xy(x^2-y^2)}\right\}$, are now the prime candidates for the order parameter of Sr$_2$RuO$_4$.
