发表机构
Indian Institute of Technology Kharagpur（印度理工学院卡拉格普尔分校）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过自洽Bogoliubov--de Gennes方法，发现单层NbSe$_2$在面内磁场下可诱导对称性选择的三重态配对，其对称性由母体单重态决定，为场可调混合宇称超导提供平台。
AI 中文摘要
我们研究了单层NbSe$_2$（一种Ising超导体）在面内Zeeman场$h_x$下的超导电性，重点关注对称性选择的等自旋三重态配对的涌现。利用自洽Bogoliubov--de Gennes方法，结合单层NbSe$_2$在三角晶格上的实际跃迁参数，我们确定了在位、最近邻和次近邻配对通道中，在一系列化学势$\mu$下能量上有利的单重态配对态，并绘制了$(h_x,\mu)$平面上的相应相图。动量分辨分析揭示了序参量中来自布里渊区$\Gamma$、$K$和$K'$点周围的不同主导贡献。我们发现，在打开三重态相互作用通道后，面内磁场有助于诱导三重态配对，其对称性由母体单重态决定。对于非局域配对通道，手性-$d$配对在能量上有利，并诱导出具有相反手性的手性-$p$等自旋三重态分量。我们进一步发现，与衬底耦合和静电门控相关的Rashba自旋轨道耦合会抑制超导序并降低临界场。我们的结果建立了母体单重态凝聚体的对称性与涌现的三重态超导电性之间的直接联系，凸显了单层NbSe$_2$作为场可调混合宇称超导态的有前景平台。
英文摘要
We investigate superconductivity in monolayer NbSe$_2$, an Ising superconductor, under an in-plane Zeeman field $h_x$, focusing on the emergence of symmetry selected equal-spin triplet pairing. Using a self-consistent Bogoliubov--de Gennes approach with realistic hopping parameters for monolayer NbSe$_2$ on a triangular lattice, we determine the energetically favored singlet pairing states in a range of chemical potentials $μ$ for onsite, nearest-neighbor, and next-nearest-neighbor pairing channels, and map the resulting phase diagram in $(h_x,μ)$ plane. A momentum-resolved analysis reveals distinct dominant contributions in order parameters arise from the surroundings of $Γ$, $K$, and $K'$ points of the Brillouin zone. We find that an in-plane magnetic field helps to induce a triplet pairing whose symmetry is determined by the parent singlet state, upon opening the triplet interaction channel. For the nonlocal pairing channels, chiral-$d$ pairing is energetically favored and it induces chiral-$p$ equal-spin triplet component with opposite chirality. We further find that Rashba spin-orbit coupling, relevant to substrate coupling and electrostatic gating, suppresses the superconducting orders and reduces the critical field. Our results establish a direct link between the symmetry of the parent singlet condensate and the emergent triplet superconductivity, highlighting monolayer NbSe$_2$ as a promising platform for field-tunable mixed-parity superconducting states.
Comments14 pages, 16 figures
