论文标题
Hofstadter-Moiré蝴蝶在扭曲的三层石墨烯中
Hofstadter-Moiré Butterfly in Twisted Trilayer Graphene
论文作者
论文摘要
镜子对称扭曲的三层石墨烯（TTLG）由平均扭曲的双层石墨烯（TBLG）样带和奇特的奇特式狄拉克（Dirac）样带组成。在这里，我们研究了TTLG的镜像对称和镜像Hofstadter-Moiré（HM）分形带。在实验可访问的电荷密度下，在镜子对称的TTLG中鉴定出一种新型的量子平价大厅状态。这种镜子对称保护拓扑相表现出同时量化的大厅和纵向电阻。还研究了位移场对TTLG和拓扑相变的HM分形带的影响。电位位移场的应用导致在电荷中立点处出现了一系列扭曲角度的弱分散带。这种零能状态位于中层。它是通过与施加位移场成正比的能量缩放的能量间隔从HM频谱中分离出来的，使其成为宿主相关拓扑状态的主要候选者。
Mirror symmetric twisted trilayer graphene (tTLG) is composed of even parity twisted bilayer graphene (tBLG)-like bands and odd parity Dirac-like bands. Here, we study the mirror-symmetric and mirror-asymmetric Hofstadter-Moiré (HM) fractal bands of tTLG. A novel quantum parity Hall state is identified in mirror-symmetric tTLG at experimentally accessible charge densities. This mirror symmetry-protected topological phase exhibits simultaneous quantized Hall and longitudinal resistances. The effects of the displacement field on the HM fractal bands of tTLG and topological phase transitions are also studied. The application of an electric displacement field results in an emergent weakly dispersive band at the charge neutrality point for a range of twist angles. This zero-energy state resides in the middle layer. It is isolated from the HM spectrum by an energy gap that scales proportional to the applied displacement field, making it a prime candidate to host correlated topological states.
