论文标题
莫伊尔异质结构中的激发量量子厅层次结构
Excitonic fractional quantum Hall hierarchy in Moiré heterostructures
论文作者
论文摘要
我们考虑在系统中的分数量子厅状态，其中两个平坦的Chern Number $ C = \ pm 1 $ bands由大约保守的“山谷”索引标记，并通过时间反向对称性互换。在填充因子$ν= 1 $时，此设置接收了激子相关阶段的异常层次结构，中性的粒子孔对对完全极化的“轨道轨道铁磁铁”的母体状态，所有电子都占据了一个山谷。由于基础带的Chern数字，激子经历了有效的磁场。这阻碍了他们的凝结，而有利于各种晶体订单，并散发出无间隙的液态。所有这些都具有相同的量化充电厅响应，并且是电气不可压缩的，但其边缘结构，轨道磁化以及山谷和热反应的不同。我们探讨了这种情况与六角硼硝化硼基板上双层石墨烯的Moiré异质结构的相关性。
We consider fractional quantum Hall states in systems where two flat Chern number $C=\pm 1$ bands are labeled by an approximately conserved 'valley' index and interchanged by time reversal symmetry. At filling factor $ν=1$ this setting admits an unusual hierarchy of correlated phases of excitons, neutral particle-hole pair excitations of a fully valley-polarized `orbital ferromagnet' parent state where all electrons occupy a single valley. Excitons experience an effective magnetic field due to the Chern numbers of the underlying bands. This obstructs their condensation in favor of a variety of crystalline orders and gapped and gapless liquid states. All these have the same quantized charge Hall response and are electrically incompressible, but differ in their edge structure, orbital magnetization, and hence valley and thermal responses. We explore the relevance of this scenario for Moiré heterostructures of bilayer graphene on a hexagonal boron nitride substrate.
