Theory of Quantum Anomalous Hall Phases in Pentalayer Rhombohedral Graphene Moiré Structures
by RLE at MIT | Nov 21, 2024 | RLE Recent Papers
Zhihuan Dong, Adarsh S. Patri, and T. Senthil
doi: 10.1103/PhysRevLett.133.206502
Abstract:
Remarkable recent experiments on the moiré structure formed by pentalayer rhombohedral graphene aligned with a hexagonal boron nitride substrate report the discovery of a zero field fractional quantum Hall effect. These “(fractional) quantum anomalous Hall” [(F)QAH] phases occur for one sign of a perpendicular displacement field, and correspond, experimentally, to full or partial filling of a valley polarized Chern‑1 band. Such a band is absent in the noninteracting band structure. Here we show that electron-electron interactions play a crucial role, and present microscopic theoretical calculations demonstrating the emergence of a nearly flat, isolated, Chern‑1 band and FQAH phases in this system. We also study the four- and six-layer analogs and identify parameters where a nearly flat isolated Chern‑1 band emerges which may be suitable to host FQAH physics.
