发表机构
Koç University（科奇大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文揭示多带超导体超流重量中配对弛豫修正的量子几何起源，证明其由集体配对场空间中的刚度加权量子度量决定，并通过Lieb晶格计算验证了三种表述的等价性。
AI 中文摘要
在冻结配对贡献之外，多带超导体的超流重量还包含一个来自相位扭转下配对振幅自洽弛豫的修正。我们证明，该修正具有量子几何起源，但并非源于布洛赫态空间，而是源于集体配对场空间。对于平均场层面的吸引性多带Hubbard模型，控制配对响应的热力学Hessian矩阵在低于$T_c$的每个温度下均与零动量处的静态高斯配对涨落核一致。由于规范不变性将相位扭转与配对场的有限质心动量联系起来，超流重量由从Goldstone模式演化而来的本征值分支的小动量曲率决定，而弛豫修正则是配对构型流形上相应软本征矢量的刚度加权量子度量。同样的构造给出了具有相同几何修正的Ginzburg-Landau梯度系数，从而得到相干长度张量，并结合核的低频动力学得到配对质量张量。Lieb晶格计算验证了热力学、涨落核和软模式三种表述的等价性，以及超流重量对轨道嵌入的独立性。
英文摘要
Beyond the frozen-pairing contribution, the superfluid weight of a multiband superconductor contains a correction from the self-consistent relaxation of the pairing amplitudes under a phase twist. We show that this correction has a quantum-geometric origin, not in the space of Bloch states but in the space of collective pairing fields. For an attractive multiband Hubbard model at the mean-field level, the thermodynamic Hessian governing the pairing response coincides with the static Gaussian pair-fluctuation kernel at zero momentum at every temperature below $T_c$. Since gauge invariance relates a phase twist to a finite center-of-mass momentum of the pair field, the superfluid weight is set by the small-momentum curvature of the eigenvalue branch that evolves from the Goldstone mode, and the relaxation correction is a stiffness-weighted quantum metric of the corresponding soft eigenvector on the manifold of pairing configurations. The same construction yields the Ginzburg-Landau gradient coefficient with the identical geometric correction, hence the coherence-length tensor, and, with the low-frequency dynamics of the kernel, the pair-mass tensor. Lieb-lattice calculations verify the equivalence of the thermodynamic, fluctuation-kernel, and soft-mode formulations and the independence of the superfluid weight from the orbital embedding.
Comments16 pages with 1 figure
