论文标题
在4HB-TAS $ _2 $的超导状态下的nematic跨界手性
Chiral to Nematic Crossover in the Superconducting State of 4Hb-TaS$_2$
论文作者
论文摘要
大多数超导体具有各向同性的单个组件阶参数，并且由BCS理论很好地描述了超导性。非常规的多个成分超导体异常罕见，并且不理得多。在这里，我们将扫描隧道显微镜和角度分辨的宏观传输结合在一起，研究候选手性超导体，4HB-TAS $ _2 $。我们揭示了隧道电导中的准周期性一维调制，并伴有两倍的对称超导临界场。平面内临界场的强调指向nematic，非常规阶参数。但是，成像的涡流芯几乎是圆形对称的，表明各向同性阶参数。我们通过对主导性超导级参数与列表之间的竞争进行建模来调和这一明显的差异，后者出现在正常阶段附近。我们的结果强烈支持在4HB-TAS $ _2 $中存在两个组件超导性，并可以为具有共存的充电顺序和超导率的其他系统提供有用的见解。
Most superconductors have an isotropic, single component order parameter, and are well described by the BCS theory for superconductivity. Unconventional, multiple components superconductors are exceptionally rare and are much less understood. Here, we combine scanning tunneling microscopy and angle-resolved macroscopic transport to study the candidate chiral superconductor, 4Hb-TaS$_2$. We reveal quasi-periodic one-dimensional modulations in the tunneling conductance accompanied by two-fold symmetric superconducting critical field. The strong modulation of the in-plane critical field, points to a nematic, unconventional order parameter. However, the imaged vortex core is nearly circular symmetric, suggesting an isotropic order parameter. We reconcile this apparent discrepancy by modeling a competition between a dominating chiral superconducting order parameter and a nematic one, the latter emerges close to the normal phase. Our results strongly support the existence of two-component superconductivity in 4Hb-TaS$_2$ and can provide useful insights to other systems with coexistent charge order and superconductivity.
