论文标题
SR $ _2 $ ruo $ _4 $的两部分超导订单参数的超声证据
Ultrasound evidence for a two-component superconducting order parameter in Sr$_2$RuO$_4$
论文作者
论文摘要
准2D金属SR $ _2 $ ruo $ _4 $是特征在于非常规的超导体之一，但其超导订单参数的性质仍然是高度争议的。该信息对于确定库珀对的配对机制至关重要。在这里，我们使用超声速度来探测SR $ _2 $ ruo $ _4 $的超导状态。该热力学探针对称敏感，可以帮助识别超导级对称性。确实，我们观察到剪切弹性常数$ c_ {66} $的急剧跳跃，因为在$ t_c $的超导过渡中温度升高。这直接暗示超导顺序参数具有两部分性质。基于对称参数，并给出了SR $ _2 $ ruo $ _4 $的其他已知属性，我们讨论了哪些状态与此要求兼容，并提出了两个组件订单参数，即$ \ lbrace d_ {xz}; d_ {yz} \ rbrace $是最有可能的候选人。
The quasi-2D metal Sr$_2$RuO$_4$ is one of the best characterized unconventional superconductors, yet the nature of its superconducting order parameter is still highly debated. This information is crucial to determine the pairing mechanism of Cooper pairs. Here we use ultrasound velocity to probe the superconducting state of Sr$_2$RuO$_4$. This thermodynamic probe is symmetry-sensitive and can help to identify the superconducting order symmetry. Indeed, we observe a sharp jump in the shear elastic constant $c_{66}$ as the temperature is raised across the superconducting transition at $T_c$. This directly implies that the superconducting order parameter is of a two-component nature. Based on symmetry argument and given the other known properties of Sr$_2$RuO$_4$, we discuss what states are compatible with this requirement and propose that the two-component order parameter, namely $\lbrace d_{xz}; d_{yz} \rbrace$, is the most likely candidate.
