标题： 多重配对态和近向列量子临界点超导性的温度依赖能隙各向异性 显示英文标题

标题： Multiple pairing states and temperature-dependent gap anisotropy for superconductivity near a nematic quantum-critical point

摘要： 强关联材料中的超导性出现在电荷密度波或向列序的附近，并被认为是由相应序参量的量子临界（QC）涨落介导的。 我们认为可以从间隙$\Delta (\theta)$的角度依赖性中提取 QC 配对的特征。 我们考虑由 QC 向列涨落引起的配对，并表明在相同的对称性（我们的情况是$s-$波）内存在多个配对不稳定性，其转变温度$T_{c,n}$接近。 相应的$\Delta_n (\theta)$在费米面上沿$8n$次改变符号。 只有具有最高$T_{c,0} =T_c$的解会发展，但其他间隙成分在$T_c$以下被诱导，并在$T_{c,n}$以下得到共振增强。 这导致了$T_c$以下间隙的角依赖性的强烈变化。 在远离量子临界点时，这种效应会变得弱得多。 显示英文摘要

摘要： Superconductivity in many strongly correlated materials appears in proximity to a density-wave or nematic order and is believed to be mediated by quantum-critical (QC) fluctuations of the corresponding order parameter. We argue that fingerprints of QC pairing can be extracted from the angular dependence of the gap $\Delta (\theta)$. We consider pairing by QC nematic fluctuations and show that there exist multiple pairing instabilities within the same symmetry ($s-$wave in our case), with closely spaced transition temperatures $T_{c,n}$. The corresponding $\Delta_n (\theta)$ change sign $8n$ times along the FS. Only the solution with the highest $T_{c,0} =T_c$ develops, but other gap components are induced below $T_c$ and get resonantly enhanced below $T_{c,n}$. This gives rise to strong variation of the angular dependence of the gap below $T_c$. The effect gets much weaker away from a quantum-critical point.