Interacting valley Chern insulator and its topological imprint on moire superconductors

Article

关键词: NON-ABELIAN STATISTICS;    QUANTUM;    STATES;    CLASSIFICATION;    FERMIONS;    PARITY;   

DOI  :  10.1103/PhysRevB.100.155138

来源: SCIE

【 摘 要 】

One salient feature of systems with moire superlattice is that the Chern number of minibands originating from each valley of the original graphene Brillouin zone becomes a well-defined quantized number because the miniband from each valley can be isolated from the rest of the spectrum due to the moire potential. Then a moire system with a well-defined valley Chern number can become a nonchiral topological insulator with U(1) x Z(3) symmetry and a Z classification at the free fermion level. Here we demonstrate that the strongly interacting nature of the moire system reduces the classification of the valley Chern insulator from Z to Z(3), and it is topologically equivalent to a bosonic symmetry-protected topological state made of local boson operators. We also demonstrate that even if the system becomes a superconductor when doped away from the valley Chern insulator, the valley Chern insulator still leaves a topological imprint as the localized Majorana fermion zero mode in certain geometric configuration.

【 授权许可】

Free