论文标题
来自本地带几何形状的配对密度波
Pair Density Waves from Local Band Geometry
论文作者
论文摘要
开发了一种带杆的形式主义，用于计算具有轨道依赖性配对的二维多轨超导体中的超流体重量。据发现，在这种情况下，在布里渊区的某些地区，频带几何超流体刚度张量可能是局部非阳性点的。当这些区域足够大或包括淋巴结奇点时，由于配对波动，总的超氟体重变为非阳性偏剂，从而导致BCS状态过渡到配对密度波（PDW）。该几何BCS-PDW过渡是在两轨超导体的背景下研究的，并在通用拓扑平面谱带中建立了几何BCS-PDW过渡的证明。
A band-projection formalism is developed for calculating the superfluid weight in two-dimensional multi-orbital superconductors with an orbital-dependent pairing. It is discovered that, in this case, the band geometric superfluid stiffness tensor can be locally non-positive-definite in some regions of the Brillouin zone. When these regions are large enough or include nodal singularities, the total superfluid weight becomes non-positive-definite due to pairing fluctuations, resulting in the transition of a BCS state to a pair-density wave (PDW). This geometric BCS-PDW transition is studied in the context of two-orbital superconductors, and proof of the existence of a geometric BCS-PDW transition in a generic topological flat band is established.
