Discovery of Tunable Quantum Anomalous Hall Octet

  • Bernal bilayer graphene is a naturally occurring system with neither spin-orbit coupling nor moiré complex.

  • Quantum anomalous Hall (QAH) octet, i.e., eight states exhibiting quantum Hall effect at zero magnetic field, was theoretically predicted and experimentally observed.

  • Ferromagnetism, ferroelectricity, and QAH effect coexist and  cooperate  in  these  competing  ground  states,  thus switchable via magnetic/electric field and carrier sign.

  • Bilayer graphene offers a potential platform for quantum information, quantum computing, and quantum sensing.

  • Few-layer  quasi-1D  materials  such  as  Bi4I4  and  Bi4Br4have been predicted to be the time-reversal counterpart !

Additional Materials