发表机构
Indian Institute of Technology Madras（印度马德拉斯理工学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究通过chargon（希格斯）构造分析掺杂kagome U(1)狄拉克自旋液体，发现能带效应导致电荷序先于超导出现，并预测了具体的电荷序、残余配对相和环流场等可观测特征。
AI 中文摘要
对量子自旋液体进行掺杂预期会产生超导体。在kagome晶格上，由于能带结构而非相互作用，掺杂首先产生电荷序。在其U(1)狄拉克自旋液体的chargon（希格斯）构造中，两个规范分量在正方和三角晶格上简并，但被线图效应劈裂：一个分量色散，在$-(1+\sqrt6)t$处有四个极小值；另一个分量在$-2t$处有两个完全平坦的最低带。只有色散分量凝聚，凝聚发生在宽度恰好为$(\sqrt6-1)t$的裸质量窗口内，在此窗口中，掺杂自旋液体在$M$、$K$和$K/2$星上形成电荷和环流晶体，物理U(1)对称性未破缺：这是一种不超导的chargon希格斯相。其配对通道是$\mathbb{Z}_2$后裔的配对通道，即配对密度波，均匀的$d+id$在领头阶和$M$星上的所有阶都被排除。投影对称群将四次竞争约化为一个角度，在该角度上，投影的格点排斥恰好位于$M$/$K/2$边界，该方向在重整化下受$O(4)\times U(1)$保护至所有阶，尽管晶格匹配给出物理耦合的离射线分量。竞争的$M$星晶体在六次阶上简并，仅在八次阶上分裂。电荷扇区携带其自身的分类，即未掺杂双线性-单极子目录的带电对应物，该目录不包含携带电荷的算符；它将掺杂莫特绝缘体和kagome金属放在一个$F$-不可约表示网格上，由电荷序不可约表示（此处为$F_3$，彼处为$F_1$）和朗道三次项分隔。预测：$C_2$-奇（$F_3$）电荷序，无三次不变量；周期为$h/4e$或$h/6e$的残余配对相；在herbertsmithite的$^{17}$O和$^{35}$Cl处约十高斯的环流场；以及，如果$\Gamma$通量与凝聚体一起有序，则电荷和电流序在凝聚尺度以下同时出现。
英文摘要
Doping a quantum spin liquid is expected to produce a superconductor. We show that for the Dirac spin liquid on the kagome lattice the doped charge orders first. The charge is carried by a chargon doublet whose two gauge components are degenerate on the square and triangular lattices, and the kagome lattice, as the line graph of the honeycomb lattice, splits them. One component disperses and condenses in four valleys. The other has flat lowest bands and stays empty over a window in the bare mass whose width, $(\sqrt6-1)t$, follows from the band structure alone. Within that window, in the mean-field chargon theory constructed from the projective symmetry group of the spin liquid, the doped state forms charge and loop-current crystals with the electromagnetic U(1) unbroken and no superconductivity. Pairing requires a gapped descendant of the spin liquid as the parent and then takes the form of a pair-density wave, with no uniform $d+id$ channel at leading order and none at any order for the crystals at the $M$ point. The predicted charge order is odd under the twofold rotation and has no cubic invariant, which distinguishes it from the charge order of the kagome metals.
Comments59 pages, 10 figures, 6 tables
