发表机构
University of Washington; University of Tennessee; Los Alamos National Laboratory（华盛顿大学; 田纳西大学; 洛斯阿拉莫斯国家实验室）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文通过Haldane-Holstein模型在部分填充下，证明强电子-声子耦合可稳定玻色子分数陈绝缘体及量子反常霍尔晶体，揭示其作为拓扑相形成路径的新作用。
AI 中文摘要
电子-声子耦合通常被认为会抑制能带拓扑，将拓扑能带绝缘体驱动为平庸相。在此，我们表明，利用拓扑能带部分填充下的典型Haldane-Holstein模型，强电子-声子耦合反而能够稳定物质的拓扑相。电子-声子耦合扮演双重角色：它产生关联载流子的长程相互作用，并且在吸引通道中，还将它们束缚成玻色子对。对于自旋电子，它将相反自旋配对成电荷为$2e$的双极化子，在填充$\u03bd=1/2$时形成具有电荷为$e$的半子激发的玻色子分数陈绝缘体（FCI）。调节能带拓扑和耦合强度，描绘出包含该玻色子FCI、在$M$和$K$点凝聚的超导体以及几种电荷有序固体的丰富相图。对于自旋极化电子，强耦合反而在$\u03bd=1/3$时稳定了$C=2$的量子反常霍尔晶体（QAHC）。因此，电子-声子耦合在部分填充的陈带中成为通往拓扑的路径，而非阻碍。
英文摘要
Electron-phonon coupling is generally expected to suppress band topology, driving a topological band insulator into a trivial phase. Here we show that, using the prototypical Haldane-Holstein model at partial filling of a topological band, strong electron-phonon coupling can instead stabilize topological phases of matter. The electron-phonon coupling plays a double role: it generates the longer-range interactions that correlate the carriers and, in the attractive channel, also binds them into bosonic pairs. For spinful electrons, it pairs opposite spins into charge-$2e$ bipolarons that form a bosonic fractional Chern insulator (FCI) at filling $ν=1/2$ with charge-$e$ semionic excitations. Tuning the band topology and the coupling strength maps out a rich phase diagram containing this bosonic FCI, superconductors condensed at the $M$ and $K$ points, and several charge-ordered solids. For spin-polarized electrons, strong coupling instead stabilizes a $C=2$ quantum anomalous Hall crystal (QAHC) at $ν=1/3$. Electron-phonon coupling thus emerges as a route to, rather than an obstruction against, topology in partially filled Chern bands.
Comments9+5 pages, 6+4 figures
