论文标题
竞争超导通道的NBSE2单层中的结节和nematic超导阶段
Nodal and nematic superconducting phases in NbSe2 monolayers from competing superconducting channels
论文作者
论文摘要
在其二维（2D）形式中的过渡金属二分裂基因层（如2H-NBSE2）与准粒子旋转具有超导性，牢固地固定在垂直于基础平面的方向上。这使他们能够承受超过Pauli极限超过超导性的极高磁场。使用在基础平面中旋转的场的场角分辨磁度实验，我们研究了上临界场（HC2）的场角依赖性，这直接反映了超导顺序参数的对称性。我们观察到在两倍对称性上超级伪造的六倍的淋巴结对称性。这与HC2附近的淋巴结拓扑超导相的理论预测以及列明超导状态。我们证明，在NBSE2中，这种非常规的超导状态可能是由于存在几个相互竞争的超导通道而产生的。
Transition metal dichalcogenides like 2H-NbSe2 in their two-dimensional (2D) form exhibit Ising superconductivity with the quasiparticle spins are firmly pinned in the direction perpendicular to the basal plane. This enables them to withstand exceptionally high magnetic fields beyond the Pauli limit for superconductivity. Using field-angle-resolved magnetoresistance experiments for fields rotated in the basal plane we investigate the field-angle dependence of the upper critical field (Hc2), which directly reflects the symmetry of the superconducting order parameter. We observe a six-fold nodal symmetry superposed on a two-fold symmetry. This agrees with theoretical predictions of a nodal topological superconducting phase near Hc2, together with a nematic superconducting state. We demonstrate that in NbSe2 such unconventional superconducting states can arise from the presence of several competing superconducting channels.
